::What is the Computer Misuse Act?
This bill is intented to protect data stored on computer from unauthorised access and/or modification. Examples of these are hacking and virus making, which although are not named by the law are by their natured covered by it. Abuses of these kinds are most often found in the academic sector, especially with student authors (Woods-Wilson, 2009. para 1).
::Unauthorised access (section 1)
This section of the law covers using a computer to gain unauthorised access to any program or data held on any computer. This (for example) could be using a computer to guess passwords to bank accounts or to hack into a web-server to read sensitive data. The computer and data need not be particular (Computer Misuse Act, 1990. sect 1.2) only the access unauthorised. This means than on a very low level, logging into someone elses 'facebook' account without their permission could be illegal.
::Unauthorised access with intent to commit a further crime (section 2)
More serious than section 1, this part of the law is designed to prevent criminals using computers to commit further crimes. Not only is unauthorised access prohibitied, but if there is proven intent to commit a further crime, regardless of whether its commited or not, (Computer Misuse Act, 1990. sect 2.3).
::Modification (section 3)
This is the most serious aspect of the law covering unauthorised modification of the contents of any computer (Computer Misuse Act, 1990. sect 3.1.a). Alot of UK law is based around property and digital data is regarded as such. Although this law doesn't cover physical damage to the computer (Computer Misuse Act, 1990. sect 3.6) it does cover any impairment if a computer. Under section 3.2 it is illegal to (without authorisation) impair the operation of a computer, hinder access to any program or data, or impair the  operation of a program or the reliability of data. Examples of such illegal activity are 'viruses' that destroy or modify computer data and 'botnet' programs which allow a user to take over the host computer.
::Penalities
Depending on the seriousness of the crime (described above) and how a person is convicted, punishments are as follows:
Offences under section 1:
up to 6months in prison and/or a fine up to £2000 (level 5 on the standard scale)
Offences under section 2:
on summary: same as section 1 with a fine up to the statutory maximum
on indictment: prison term up to 5 years and/or a fine
Offences under section 3:
on summary: same as section 2
on indictment: same as section 2
::Where the does the law apply?
The law covers any offences commited on British soil.
- If the computer used to access or modified information was on British soil
- The computer storing the accessed or modified information was on British soil
It is irrevelant whether the person commiting the offence is a British citizen or not (Computer Misuse Act, 1990. sect 9).
::Limits of the law
As you can see above, the punishments for offences under this law are fairly weak especially in section 3,  and as a result viruses & hacking are still a danger in the UK. Also since this isn't an international law, with the expansion of the internet globally there is less protection from offences commited abroad that impact users in the UK.
::Impact on the computing community
Since modern computing is an international affair with no one governing body or controlling organisation, it is down to individual community and users to do what they can. Within the UK, computer experts have a responsibility not to abuse their position & knowledge to commit offences under the law but this offers littlle protection from attacks that come from outside UK borders. A sucessful conviction relys on identifying the criminal, proving their intent & guilt and also bringing them to the UK for trial, all of which is very hard especially because a person capable of such action is normally able to hide their identify sucessfully.
::References
 1990. Computer Misuse Act, Available at: http://www.opsi.gov.uk/acts/acts1990/ukpga_19900018_en_1 [Accessed November 22, 2009].
Woods-Wilson, P., GUIDANCE ON COMPUTER MISUSE ACT. Available at: http://www.lancs.ac.uk/iss/rules/cmisuse.htm [Accessed November 22, 2009].

::Questions
1. Using a computer to access data without authorisation is covered by...of the law.
a) section 1 <
b) section 2
c) section 3
d) no part
Reason: section 1 is all about accessing data without authorisation
2. Virus creation is specifically prohibited under the law?
a) No, viruses aren't mentioned in the law
b) Yes viruses are nasty
c) Yes viruses slow down computers
d) No, only if the virus can be used to commit an offence under the law <
Reason: the law doesn't prohibit the creation of viruses, or indeed using them on equipment/data with the owners permission however if the virus does access or modify data or impair a computer without authorisation it becomes illegal
3. Someone uses a laptop as a hammer to destroy a CD containing sensitive data, would they be convicted under the Computer Misuse Act?
a) It would depend on whether they were authorised to access the data on the CD
b) Yes, this is using computer equipment for modification of data
c) No, phyiscal damage isn't covered by this law <
d) It would depend on whether they were authorised to modify the data on the CD
Reason: section 3.6 "[using a computer for ] 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"
4. A security tester, based in the UK, who tests computer security by attempting to hack into them is commiting an offence under the Computer Misuse Act if...
a) He is authorised to attempt to gain access to they systems 
b) The computer he used and the computer attacked arent in the UK
c) He uses the access he gained to commit a further crime <
d) He doesn't test the system properly
Reason: Section 2 of the law states that any access to computer programs or data which is done with the intent to commit further crimes is illegal
5. To be guilty of the offence in section 1 of the Computer Misuse Act 1990 what must a defendant cause a computer to do?
a) Hack another computer <
b) Commit a fraud
c) Perform any function
d) Obtain money
Reason: part of hacking is accessing data without authorisation on a computer which is illegal under this law
6. What is the purpose of this law?
a) An act to make provision for securing computer material against unauthorised access or modification; and for connected purposes <
b) To deter hacking, virus making and other disruptive behaivour
c) To protect on individiuals data
d) To protect interlectual property against theft or plagaism

Reason: Stated on the first page of the act

7. A person is convicted of accessing the central university computer and modifying their grades in the student records, what is the maximum penalty they face?
a) 6 month in prison
b) 5 years in prison and fine to the statury maximum <
c) 5 years in prison and a fine up to £2000
d) 10 years in prison and an unlimited fine

Reason: Their offence is covered by second 3 of the act (unauthorised modifcation if computer material) and the law states this is the maximum punishment

8. Is there following statement correct and why?
"System administrators have a legal obligation (as part of this act) to protect their systems from hackers"
a) True, sysadmins are required to do all they can to protect data
b) False, the law has no obligation <
c) False, the law doesn't specifically mention hacking
d) True, sysadmins are required to stop hackers at all costs

Reason: This is beyond the scope of this law but may be coverd under some contract law

9. A person installs a new piece of software on their computer which subsequently slows it down impairing their use of it. Would they be protected by the computer misuse act?
a) No, the act doesn't cover consumer software
b) Yes, the software has impaired the operation of t computer so section 3 of the law applies
c) Yes, the user didn't give the software permission slow down their computer
d) No, the user gave authorisation for the software to be installed and run therefore none of this law applies <

Reason: This law deals with unauthorised access, modification and impairment only. Not authorised actions.

10. Where does the Computer Misuse Act 1990 apply?
a) Throughout the European Union
b) The globe
c) The United Kingdom <
d) England

Reason: This is a British Law and applies to offences committed within the United Kingdom as described in the act