BALTIMORE — The National Security Agency ended Saturday its dragnet collection of data on phone calls that use domestic carriers — the most significant change in American intelligence-gathering since Edward Snowden revealed details of the agency's programs two years ago.
Under the Patriot Act, approved by Congress after the attacks of Sept. 11, 2001, the NSA was permitted to gather records about phone calls and hunt through them for connections to al-Qaida and other groups.
The authority for that system expired Saturday. Under a new law, the NSA must ask phone companies for records on a case-by-case basis. That gives the agency access to a greater volume of phone records than before.
The Office of the Director of National Intelligence said Friday that the new program limits the data collected to “the greatest extent reasonably practicable.”
The end of the program is a victory for Snowden, a former NSA contractor, and his supporters, who say the NSA has too much power to gather data on Americans. While the documents he released to reporters pushed the government to re-evaluate its approach to spying, they are now more than two years old, and there are signs the NSA has changed its methods.
Alex Abdo, an attorney with the American Civil Liberties Union, said he is concerned that the Snowden documents provided only a brief glimpse of how the nation's intelligence agencies operate.
In the most controversial program revealed by Snowden, the NSA collected what it called telephone metadata — records of numbers dialed, times and lengths of calls — in an effort to identify communications among terrorists. Officials say the agency did not eavesdrop on the calls.
Official reviews of the program concluded that it had not helped uncover a single terrorist plot and offered few benefits.
