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Last updated: Saturday 09 August 2025 @ 08:55:10

CMA Reference

UK Legal Reference Sheet – Computer Misuse Act 1990 & GDPR (2024 Summary)

Computer Misuse Act 1990 (CMA)

Section 1 – Unauthorised Access

  • It is an offence to knowingly gain unauthorised access to any computer system.
  • Example: Logging in to an account without permission, even just to look.

Section 2 – Unauthorised Access with Intent

  • Accessing systems without permission with intent to commit further crimes, e.g., fraud or data theft.

Section 3 – Unauthorised Acts with Intent to Impair

  • Doing something that causes damage, e.g., deploying malware, deleting files, or disrupting systems.

Section 3ZA – Causing Serious Damage

  • Aggravated offence where serious harm is caused to national security, health, or economic interests.

Section 3A – Making, Supplying or Obtaining Hacking Tools

  • Illegal to make or distribute tools used to commit CMA offences.

UK GDPR (General Data Protection Regulation)

Key Principles (Article 5)

  • Lawfulness, fairness, transparency
  • Purpose limitation
  • Data minimisation
  • Accuracy
  • Storage limitation
  • Integrity and confidentiality

Article 32 – Security of Processing

  • Organisations must implement appropriate technical and organisational security.

Article 33 – Breach Notification

  • Must notify ICO within 72 hours if a data breach risks individual rights.

Article 34 – Communication to Data Subjects

  • If a breach is high risk to individuals, the affected persons must also be informed without undue delay.

Notes for Incident Response

  • Always preserve the chain of custody.
  • Ensure actions do not breach privacy laws.
  • Attribution must be based on evidence, not suspicion.