The Computer Misuse Act became law in August 1990. Under the Act hacking and the introduction of viruses are criminal offences. Computer misuse act is a make illegal to access someone computer or account without their permission.

1. Unauthorised access to computer material

• to use another person's ID and password in order to access a computer, use data or run a program;

• to alter, delete, copy, or move a program or data, or simply to output a program or data; or

• to lay a trap to obtain a password.

2. Unauthorised access to a computer system with intent to commit or facilitate the commission of a further offence

3. Unauthorised modification of computer material

Prosecution of Computer Misuse Act 1990
Computer Misuse Act 1990, s 3 Unauthorised modification.
A Web designer created Gokar, Redesi, Admirer mass mailing viruses that infected 22,000 PCs worldwide. Defendant pleaded guily, convicted and sentenced to two years jail. Appeal against sentence failed

Southwark Crown Court 21/01/2003