Client P used to work for A&A LTD doing data input, however due to his pay being reduced by his employer without him being informed, he left, but before he did he put a virus on the database.

What cases and legislation link to this

The scenario you described involves several potential legal issues, including employment law, data protection law, and criminal law. Here are some relevant cases and legislations that may apply:

1. Employment Law:
- Case: Constructive Dismissal - You mentioned that Client P left the company due to a pay reduction without being informed. The concept of constructive dismissal may be applicable here.
- Legislation: Employment Rights Act 1996 (UK) - This act governs the rights and responsibilities of both employers and employees, including provisions related to unfair dismissal and constructive dismissal.

2. Data Protection Law:
- Case: Unauthorized Access/Data Breach - If Client P intentionally placed a virus on the company's database, it could potentially be considered unauthorized access or a data breach.
- Legislation: General Data Protection Regulation (GDPR) - This regulation applies in the European Union and governs the processing and protection of personal data. It imposes obligations on organizations to safeguard data and report data breaches.

3. Criminal Law:
- Case: Unauthorized Access/Computer Misuse - Placing a virus on a database could potentially be considered unauthorized access or computer misuse, depending on jurisdiction-specific laws.
- Legislation: Computer Misuse Act 1990 (UK) - This act specifically addresses offenses related to unauthorized access, computer hacking, and introducing viruses into computer systems.

Please note that the specific application and interpretation of these cases and legislations would depend on the relevant jurisdiction and the specific circumstances of the case. It is advisable to consult with a legal professional to obtain accurate and up-to-date advice.