Computer Misuse Act 1990 (UK)
Computer misuse offences
1.(1) A person is guilty of an offence if -
(a) he causes a computer to perform any function with intent to
secure access to any program or data held in any computer;
(b) the access he intends to secure is unauthorised; and
(c) he knows at the time when he causes the computer to perform the
function that that is the case.
(2) The intent a person has to have to commit an offence under this
section need not be directed at -
(a) any particular program or data;
(b) a program or data of any particular kind; or
(c) a program or data held in any particular computer.
(3) A person guilty of an offence under this section shall be liable on
summary conviction to imprisonment for a term not exceeding six months
or to a fine not exceeding level 5 on the standard scale or to both.
Computer Misuse Act 1990 (UK) Section 2
2.(1) A person is guilty of an offence under this section if he commits
an offence under section 1 above ("the unauthorised access offence")
with intent -
(a) to commit an offence to which this section applies; or
(b) to facilitate the commission of such an offence (whether by himself
or by any other person);
and the offence he intends to commit or facilitate is referred to below
in this section as the further offence.
(2) This section applies to offences -
(a) for which the sentence is fixed by law; or
(b) for which a person of twenty-one years of age or over (not
previously convicted) may be sentenced to imprisonment for a term of
five years (or, in England and Wales, might be so sentenced but for
the restrictions imposed by section 33 of the Magistrates' Courts
Act 1980).
(3) It is immaterial for the purposes of this section whether the further
offence is to be committed on the same occasion as the unauthorised
access offence or on any future occasion.
(4) A person may be guilty of an offence under this section even though
the facts are such that the commission of the further offence is
impossible.
(5) A person guilty of an offence under this section shall be liable -
(a) on summary conviction, to imprisonment for a term not exceeding
six months or to a fine not exceeding the statutory maximum or to
both; and
(b) on conviction on indictment, to imprisonment for a term not
exceeding five years or to a fine or to both.
Computer Misuse Act 1990 (UK) Section 3
3.(1) A Person is guilty of an offence if -
(a) he does any act which causes an unauthorised modification of the
contents of any computer; and
(b) at the time when he does the act he has the requisite intent and the
requisite knowledge.
(2) For the purposes of subsection (1)(b) above the requisite intent is an
intent to cause a modification of the contents of any computer and by so
doing -
(a) to impair the operation of any computer;
(b) to prevent or hinder access to any program or data held in any
computer; or
(c) to impair the operation of any such program or the reliability of any
such data.
(3) The intent need not be directed at -
(a) any particular computer;
(b) any particular program or data or a program or data of any
particular kind; or
(c) any particular modification or a modification of any particular
kind.
(4) For the purposes of subsection (1)(b) above the requisite knowledge is
knowledge that any modification he intends to cause is unauthorised.
(5) It is immaterial for the purposes of this section whether an unauthorised
modification or any intended effect of it of a kind mentioned in
subsection (2) above is, or is intended to be, permanent or merely
temporary.
(6) For the purposes of the Criminal Damage Act 1971 a modification of
the contents of a computer shall not be regarded as damaging any
computer or computer storage medium unless its effect on that computer
or computer storage medium impairs its physical condition.
(7) A person guilty of an offence under this section shall be liable -
(a) on summary conviction, to imprisonment for a term not exceeding
six months or to a fine not exceeding the statutory maximum or to
both; and
(b) on conviction on indictment, to imprisonment for a term not
exceeding five years or to a fine or to both.
Computer Misuse Act 1990 (UK) Section 4
Jurisdiction
4.(1) Except as provided below in this section, it is immaterial for the
purposes of any offence under section 1 or 3 above -
(a) whether any act or other event proof of which is required for
conviction of the offence occurred in the home country concerned; or
(b) whether the accused was in the home country concerned at the time
of any such act or event.
(2) Subject to subsection (3) below, in the case of such an offence at least
one significant link with domestic jurisdiction must exist in the
circumstances of the case for the offence to be committed.
(3) There is no need for any such link to exist for the commission of an
offence under section 1 above to be established in proof of an
allegation to that effect in proceedings for an offence under section 2
above.
(4) Subject to section 8 below, where -
(a) any such link does in fact exist in the case of an offence under
section 1 above; and
(b) commission of that offence is alleged in proceedings for an offence
under section 2 above;
section 2 above shall apply as if anything the accused intended to do or
facilitate in any place outside the home country concerned which would
be an offence to which section 2 applies if it took place in the home
country concerned were the offence in question.
(5) This section is without prejudice to any jurisdiction exercisable by a
court in Scotland apart from this section.
(6) References in this Act to the home country concerned are references -
(a) in the application of this Act to England and Wales, to England and
Wales;
(b) in the application of this Act to Scotland, to Scotland; and
(c) in the application of this Act to Northern Ireland, to Northern
Ireland.
Computer Misuse Act 1990 (UK) Section 5
5.(1) The following provisions of this section apply for the interpretation
of section 4 above.
(2) In relation to an offence under section 1, either of the following is
a significant link with domestic jurisdiction -
(a) that the accused was in the home country concerned at the time
when he did the act which caused the computer to perform the
function; or
(b) that any computer containing any program or data to which the
accused secured or intended to secure unauthorised access by doing
the act was in the home country concerned at that time.
(3) In relation to an offence under section 3, either of the following is a
significant link with domestic jurisdiction -
(a) that the accused was in the home country concerned at the time
when he did the act which caused the unauthorised modification; or
(b) that the unauthorised modification took place in the home country
concerned.
Computer Misuse Act 1990 (UK) Section 6
6.(1) On a charge of conspiracy to commit an offence under this Act
the following questions are immaterial to the accused's guilt -
(a) the question where any person became a party to the conspiracy; and
(b) the question whether any act, omission or other event occurred in
the home country concerned.
(2) On a charge of attempting to commit an offence under section 3 above
the following questions are immaterial to the accused's guilt -
(a) the question where the attempt was made; and
(b) the question whether it had an effect in the home country concerned.
(3) On a charge of incitement to commit an offence under this Act the
question where the incitement took place is immaterial to the accused's
guilt.
(4) This section does not extend to Scotland.
Computer Misuse Act 1990 (UK) Section 7
7.(1) The following subsections shall be inserted after subsection (1) of
section 1 of the Criminal Law Act 1977 -
"(1A) Subject to section 8 of the Computer Misuse Act 1990
(relevance of external law), if this subsection applies to an agreement,
this Part of this Act has effect in relation to it as it has effect in
relation to an agreement falling within subsection (1) above.
(IB) Subsection (1A) above applies to an agreement if -
(a) a party to it, or a party's agent, did anything in England and
Wales in relation to it before its formation; or
(b) a party to it became a party in England and Wales (by joining it
either in person or through an agent); or
(c) a party to it, or a party's agent, did or omitted anything in
England and Wales in pursuance of it;
and the agreement would fall within subsection (1) above as an
agreement relating to the commission of a computer misuse offence but
for the fact that the offence would not be an offence triable in England
and Wales if committed in accordance with the parties' intentions."
(2) The following subsections shall he inserted after subsection (4) of that
section -
"(5) In the application of this Part of this Act to an agreement to
which subsection (1A) above applies any reference to an offence shall be
read as a reference to what would be the computer misuse offence in
question but for the fact that it is not an offence triable in England
and Wales.
(6) In this section "computer misuse offence" means an offence
under the Computer Misuse Act 199()."
(3) The following subsections shall he inserted after section 1(1) of the
Criminal Attempts Act 1981 -
"(1A) Subject to section 8 of the Computer Misuse Act 1990
(relevance of external law), if this subsection applies to an act, what
the person doing it had in view shall be treated as an offence to which
this section applies.
(1B) Subsection (1A) above applies to an act if -
(a) it is done in England and Wales; and
(b) it would fall within subsection (1) above as more than merely
preparatory to the commission of an offence under section 3 of
the Computer Misuse Act 1990 but for the fact that the
offence, if completed, would not he an offence triable in
England and Wales."
(4) Subject to section 8 below, if any act done by a person in England and
Wales would amount to the offence of incitement to commit an offence
under this Act but for the fact that what he had in view would not be
an offence triable in England and Wales -
(a) what he had in view shall be treated as an offence under this Act for
the purposes of any charge of incitement brought in respect of that
act; and
(b) any such charge shall accordingly be triable in England and Wales.
Computer Misuse Act 1990 (UK) Section 8
8.(1) A person is guilty of an offence triable by virtue of section 4(4)
above only if what he intended to do or facilitate would involve the
commission of an offence under the law in force where the whole or any
part of it was intended to take place.
(2) A person is guilty of an offence triable by virtue of section 1(1A) of
the Criminal Law Act 1977 only if the pursuit of the agreed course of
conduct would at some stage involve -
(a) an act or omission by one or more of the parties; or
(b) the happening of some other event;
constituting an offence under the law in force where the act, omission
or other event was intended to take place.
(3) A person is guilty of an offence triable by virtue of section 1(1A) of
the Criminal Attempts Act 1981 or by virtue of section 7(4) above only
if what he had in view would involve the commission of an offence under
the law in force where the whole or any part of it was intended to take
place.
(4) Conduct punishable under the law in force in any place is an offence
under that law for the purposes of this section, however it is described
in that law.
(5) Subject to subsection (7) below, a condition specified in any of the
subsections (1) to (3) above shall be taken to be satisfied unless not
later than rules of court may provide the defence serve on the
prosecution a notice -
(a) stating that, on the facts as alleged with respect to the relevant
conduct, the condition is not in their opinion satisfied;
(b) showing the grounds for that opinion; and
(c) requiring the prosecution to show that it is satisfied.
(6) In subsection (5) above "the relevant conduct" means -
(a) where the condition in subsection (1) above is in question, what the
accused intended to do or facilitate;
(b) where the condition in subsection (2) above is in question, the
agreed course of conduct; and
(c) where the condition in subsection (3) above is in question, what the
accused had in view.
(7) The court, if it thinks fit, may permit the defence to require the
prosecution to show that the condition is satisfied without the prior
service of a notice under subsection (5) above.
(8) If by virtue of subsection (7) above a court of solemn jurisdiction in
Scotland permits the defence to require the prosecution to show that the
condition is satisfied, it shall be competent for the prosecution for
that purpose to examine any witness or to put in evidence any production
not included in the lists lodged by it.
(9) In the Crown Court the question whether the condition is satisfied
shall be decided by the judge alone.
(10) In the High Court of Justiciary and in the sheriff court the question
whether the condition is satisfied shall be decided by the judge or, as
the case may be, the sheriff alone.
Computer Misuse Act 1990 (UK) Section 9
9.(1) In any proceedings brought in England and Wales in respect of
any offence to which this section applies it is immaterial to guilt
whether or not the accused was a British citizen at the time of any act,
omission or other event proof of which is required for conviction of the
offence.
(2) This section applies to the following offences -
(a) any offence under this Act;
(b) conspiracy to commit an offence under this Act;
(c) any attempt to commit an offence under section 3 above; and
(d) incitement to commit an offence under this Act.
Computer Misuse Act 1990 (UK) Section 10
Miscellaneous and general
10. Section 1(1) above has effect without prejudice to the operation -
(a) in England and Wales or any enactment relating to powers of
inspection, search or seizure; and
(b) in Scotland of any enactment or rule of law relating to powers of
examination, search or seizure.
Computer Misuse Act 1990 (UK) Section 11
11.(1) A magistrates' court shall have jurisdiction to try an offence
under section 1 above if -
(a) the accused was within its commission area at the time when he did
the act which caused the computer to perform the function; or
(b) any computer containing any program or data to which the accused
secured or intended to secure unauthorised access by doing that act
was in its commission area at that time.
(2) Subject to subsection (3) below, proceedings for an offence under
section 1 above may be brought within a period of six months from the
date on which evidence sufficient in the opinion of the prosecutor to
warrant proceedings came to his knowledge.
(3) No such proceedings shall be brought by virtue of this section more
than three years after the commission of the offence.
(4) For the purposes of this section, a certificate signed by or on behalf
of the prosecutor and stating the date on which evidence sufficient in
his opinion to warrant the proceedings came to his knowledge shall be
conclusive evidence of that fact.
(5) A certificate stating that matter and purporting to be so signed shall be
deemed to be so signed unless the contrary is proved.
(6) In this section "commission area" has the same meaning as in the
Justices of the Peace Act 1979.
(7) This section does not extend to Scotland.
Computer Misuse Act 1990 (UK) Section 12
12.(1) If the trial on indictment of a person charged with -
(a) an offence under section 2 above, or
(b) an offence under section 3 above or any attempt to commit such an
offence the jury find him not guilty of the offence charged, they
may find him guilty of an offence under section 1 above if on the
facts shown he could have been found guilty of that offence in
proceedings for that offence brought before the expiry of any time
limit under section 11 above applicable to such proceedings.
(2) The Crown Court shall have the same powers and duties in relation to
a person who is by virtue of this section convicted before it on an
offence under section 1 above as a magistrates' court would have on
convicting him of the offence.
(3) This section is without prejudice to section 6(3) of the Criminal Law
Act 1967 (conviction of alternative indictable offence on trial on
indictment).
(4) This section does not extend to Scotland.
Computer Misuse Act 1990 (UK) Section 13
13.(1) A sheriff shall have jurisdiction in respect of an offence under
section 1 or 2 above if -
(a) the accused was in the sheriffdom at the time when he did the act
which caused the computer to perform the function; or
(b) any computer containing any program or data to which the accused
secured or intended to secure unauthorised access by doing that
act was in the sheriffdom at that time.
(2) A sheriff shall have jurisdiction in respect of an offence under section
3 above if -
(a) the accused was in the sheriffdom at the time when he did the act
which caused the unauthorised modification; or
(b) the unauthorised modification took place in the sheriffdom.
(3) Subject to subsection (4) below, summary proceedings for an offence
under section 1, 2 or 3 above may he commenced within a period of six
months from the date on which evidence sufficient in the opinion of the
procurator fiscal to warrant proceedings came to his knowledge.
(4) No such proceedings shall be commenced by virtue of this section more
than three years after the commission of the offence.
(5) For the purpose of this section, a certificate signed by or on behalf
of the procurator fiscal and stating the date on which evidence
sufficient in his opinion to warrant the proceedings came to his
knowledge shall be conclusive evidence of that fact.
(6) A certificate stating that matter and purporting to be signed shall be
deemed to be so signed unless the contrary is proved.
(7) Subsection (3) of section 31 of the Criminal Procedure (Scotland)
Act 1975 (date of commencement of proceedings) shall apply for the
purposes of this section as it applies for the purposes of that section.
(8) In proceedings in which a person is charged with an offence under
section 2 or 3 above and is found not guilty or is acquitted of that
charge, he may be found guilty of an offence under section 1 above if
on the facts shown he could have been found guilty of that offence in
proceedings for that offence commenced before the expiry of any time
limit under this section applicable to such proceedings.
(9) Subsection (8) above shall apply whether or not an offence under
section 1 above has been libelled in the complaint or indictment.
(10) A person found guilty of an offence under section 1 above by virtue
of subsection (8) above shall be liable, in respect of that offence,
only to the penalties set out in section 1.
(11) This section extends to Scotland only.
Computer Misuse Act 1990 (UK) Section 14
14.(1) Where a circuit judge is satisfied by information on oath give
by a constable that there are reasonable grounds for believing -
(a) that an offence under section 1 above has been or is about to be
committed in any premises; and
(b) that evidence that such an offence has been or is about to be
committed is in those premises;
he may issue a warrant authorising a constable to enter and search the
premises, using such reasonable force as is necessary.
(2) The power conferred by subsection (1) above does not extend to
authorising a search for material of the kinds mentioned in section
9(2) of the Police and Criminal Evidence Act 1984 (privileged,
excluded and special procedure material).
(3) A warrant under this section -
(a) may authorise persons to accompany any constable executing the
warrant; and
(b) remains in force for twenty-eight days from the date of its issue.
(4) In executing a warrant issued under this section a constable may
seize an article if he reasonably believes that it is evidence that an
offence under section 1 above has been or is about to be committed.
(5) In this section "premises" includes land, buildings, movable
structures, vehicles, vessels, aircraft and hovercraft.
(6) This section does not extend to Scotland.
Computer Misuse Act 1990 (UK) Section 15
15. The offences to which an Order in Council under section 2 of the
Extradition Act 1870 can apply shall include -
(a) offences under section 2 or 3 above;
(b) any conspiracy to commit such an offence; and
(c) any attempt to commit an offence under section 3 above.
Computer Misuse Act 1990 (UK) Section 16
16.(1) The following provisions of this section have effect for applying
this Act in relation to Northern Ireland with the modifications there
mentioned.
(2) In section 2(2)(b) -
(a) the reference to England and Wales shall be read as a reference to
Northern Ireland; and
(b) the reference to section 33 of the Magistrates' Courts Act 1980
shall be read as a reference to Article 46(4) of the Magistrates'
Courts (Northern Ireland) Order 1981.
(3) The reference in section 3(6) to the Criminal Damage Act 1971 shall
be read as a reference to the Criminal Damage (Northern Ireland) Order
1977.
(4) Subsections (5) to (7) below apply in substitution for subsections (1)
to (3) of section 7; and any reference in subsection (4) of that
section to England and Wales shall be read as a reference to Northern
Ireland.
(5) The following paragraphs shall be inserted after paragraph (1) of
Article 9 of the Criminal Attempts and Conspiracy (Northern Ireland)
Order 1983 -
"(1A) Subject to section 8 of the Computer Misuse Act 1990
(relevance of external law), if this paragraph applies to an agreement,
this Part has effect in relation to it as it has effect in relation to
an agreement falling within paragraph (1).
(1B) Paragraph (1A) applies to an agreement if -
(a) a party to it, or a party's agent, did anything in Northern
Ireland in relation to it before its formation;
(b) a party to it became a party in Northern Ireland (by joining it
either in person or through an agent); or
(c) a party to it, or a party's agent, did or omitted anything in
Northern Ireland in pursuance of it;
and the agreement would fall within paragraph (1) as an agreement
relating to the commission of a computer misuse offence but for the fact
that the offence would not be an offence triable in Northern Ireland if
committed in accordance with the parties' intentions."
(6) The following paragraph shall be inserted after paragraph (4) of that
Article -
"(5) In the application of this Part to an agreement to which
paragraph (1A) applies any reference to an offence shall he read as a
reference to what would be the computer misuse offence in question
but for the fact that it is not an offence triable in Northern Ireland.
(6) In this Article "computer misuse offence" means an offence
under the Computer Misuse Act 1990."
(7) The following paragraphs shall be inserted after Article 3(1) of that
Order -
"(1A) Subject to section 8 of the Computer Misuse Act 1990
(relevance of external law), if this paragraph applies to an act, what
the person doing it had in view shall be treated as an offence to which
this Article applies.
(1B) Paragraph (1A) above applies to an act if -
(a) it is done in Northern Ireland; and
(b) it would fall within paragraph (1) as more than merely
preparatory to the commission of an offence under section 3 of the
Computer Misuse Act 1990 but for the fact that the offence, if
completed, would not he an offence triable in Northern Ireland."
(8) In section 8 -
(a) the reference in subsection (2) to section 1(1A) of the Criminal
Law Act 1977 shall be read as a reference to Article 9(1A) of that
Order; and
(b) the reference in subsection (3) to section 1(1A) of the Criminal
Attempts Act 1981 shall be read as a reference to Article 1(1A) of
that Order.
(9) The references in sections 9(1) and 10 to England and Wales shall be
read as references to Northern Ireland.
(10) In section 11, for subsection (1) there shall he substituted -
"(1) A magistrates' court for a county division in Northern Ireland
may hear and determine a complaint charging an offence under section
1 above or conduct a preliminary investigation or preliminary inquiry
into an offence under that section if -
(a) the accused was in that division at the time when he did the act
which caused the computer to perform the function; or
(b) any computer containing any program or data to which the
accused secured or intended to secure unauthorised access by
doing that act was in that division at that time.";
and subsection (6) shall be omitted.
(11) The reference in section 12(3) to section 6(3) of the Criminal Law
Act 1967 shall be read as a reference to section 6(2) of the Criminal
Law Act (Northern Ireland) 1967.
(12) In section 14 -
(a) the reference in subsection (1) to a circuit judge shall be read as
a reference to a county court judge; and
(b) the reference in subsection (2) to section 9(2) of the Police and
Criminal Evidence Act 1984 shall be read as a reference to Article
11(2) of the Police and Criminal Evidence (Northern Ireland)
Order 1989.
Computer Misuse Act 1990 (UK) Section 17
17.(1) The following provisions of this section apply for the interpretation
of this Act.
(2) A person secures access to any program or data held in a computer if
by causing a computer to perform any function he -
(a) alters or erases the program or data;
(b) copies or moves it to any storage medium other than that in which it
is held or to a different location in the storage medium in which
it is held;
(c) uses it; or
(d) has it output from the computer in which it is held (whether by
having it displayed or in any other manner);
and references to access to a program or data (and to an intent to
secure such access) shall be read accordingly.
(3) For the purposes of subsection (2)(c) above a person uses a program
if the function he causes the computer to perform -
(a) causes the program to be executed; or
(b) is itself a function of the program.
(4) For the purposes of subsection (2)(d) above -
(a) a program is output if the instructions of which it consists are
output; and
(b) the form in which any such instructions or any other data is output
(and in particular whether or not it represents a form in which, in
the case of instructions, they are capable of being executed or, in
the case of data, it is capable of being processed by a computer)
is immaterial.
(5) Access of any kind by any person to any program or data held in a
computer is unauthorised if -
(a) he is not himself entitled to control access to the kind in
question to the program or data; and
(b) he does not have consent to access by him of the kind in question
to the program or data from any person who is so entitled.
(6) References to any program or data held in a computer include
references to any program or data held in any removable storage medium
which is for the time being in the computer; and a computer is to be
regarded as containing any program or data held in any such medium.
(7) A modification of the contents of any computer takes place if, by the
operation of any function of the computer concerned or any other
computer -
(a) any program or data held in the computer concerned is altered or
erased; or
(b) any program or data is added to its contents;
and any act which contributes towards causing such a modification shall
be regarded as causing it.
(8) Such a modification is unauthorised if -
(a) the person whose act causes it is not himself entitled to determine
whether the modification should be made; and
(b) he does not have consent to the modification from any person who
is so entitled.
(9) References to the home country concerned shall be read in accordance
with section 4(6) above.
(10) References to a program include references to part of a program.
Computer Misuse Act 1990 (UK) Section 18
18.(1) This Act may be cited as the Computer Misuse Act 1990.
(2) This Act shall come into force at the end of a period of two months
beginning with the day on which it is passed.
(3) An offence is not committed under this Act unless every act or other
event proof of which is required for conviction of the offence takes
place after this Act comes into force.