NSA Ran Pilot Program Tracking Americans' Cellphone Location Data

But decided against putting program into practice

The National Security Agency in 2010 and 2011 conducted a secret pilot project to test the collection of bulk data about the location of Americans' cellphones, but the agency ultimately decided against putting such a program into play for now, according to intelligence officials.

The existence of the pilot project, which has not previously been reported, was recently declassified by James R. Clapper, the director of national intelligence, but it has not been publicly disclosed. It was outlined in a draft answer obtained by The New York Times and written for Mr. Clapper to read at a Senate Judiciary Committee hearing on Wednesday if he is asked about the topic.