The National Security Agency said Thursday it collected more domestic call records than allowed, and as a result has been mass-deleting call records across a three-year period. The NSA said in a statement that on May 23 it "began deleting all call detail records (CDRs) acquired since 2015 under Title V of the Foreign Intelligence Surveillance Act." Weeks before the deletions began, the Office of the Director of National Intelligence reported that the NSA acquired more than 534 million domestic call records in 2017, triple the amount collected in 2016.