Proposed new surveillance laws are so broad they could allow spies to monitor people’s banking and shopping habits, MPs and peers have been told.
The draft Investigatory Powers Bill includes plans to store the online activity of everyone in the UK.
But a lesser-known clause would let the security services download personal details from “bulk” databases.
Internet privacy campaigner Jim Killock claimed it could even include things like the Tesco Clubcard scheme.
It was revealed earlier this year that GCHQ is downloading large amounts of personal data, known as “bulk personal datasets”, under old pieces of legislation.
The Home Office wants to put the practice on a firmer legal footing and has promised tougher safeguards – including six month warrants issued by the home secretary – and judicial oversight.
But Open Rights Group director Jim Killock, giving evidence to the Parliamentary committee examining the draft bill, said it appeared to suggest mass surveillance.
“What is a bulk data set? Which have been accessed and grabbed by GCHQ so far? Who might that apply to?