Millions of phone records were collected in 2012, but the paper says U.S. authorities only looked in detail at the records linked to fewer than 300 phone numbers.

A person familiar with details of the program said the figure of fewer than 300 numbers applied to the entire mass of raw telephone “metadata” collected last year by the NSA from U.S. carriers – not just to Verizon, which is the only telephone company identified in a document disclosed by Snowden as providing such data to the NSA.