Not just GCHQ, EUROPOL is in a bit of trouble too:
"The EU’s police agency, Europol, will be forced to delete much of a vast store of personal data that it has been found to have amassed unlawfully by the bloc’s data protection watchdog. The unprecedented finding from the European Data Protection Supervisor (EDPS) targets what privacy experts are calling a “big data ark” containing billions of points of information. Sensitive data in the ark has been drawn from crime reports, hacked from encrypted phone services and sampled from asylum seekers never involved in any crime."
It seems that acquiring data is addictive.