Investigatory powers – Regulation of investigatory powers. The Investigatory Powers Tribunal held that applications for, and approvals of, the obtaining of communications data by five applications for communications data (CDAs) concerning the claimants by the respondent Chief Constable had been unlawful and had to be quashed. In particular, there had been no lawful basis for having obtained the first two CDAs against the claimants by reference to a case that either had committed a criminal offence.