U.S. intelligence officials say controversial government surveillance programs have disrupted "dozens" of terrorist plots in the U.S. and more than 20 countries around the world.
U.S. intelligence agencies released newly declassified documents Saturday after lawmakers asked for more information about the surveillance programs to show their effectiveness.
The reports said that of the hundreds of millions of records of U.S. phone calls collected, only 300 were searched for additional information about the callers in 2012.
They provided no other details on the plots thwarted or the countries involved.
The Office of the Director of National Intelligence released a statement Sunday saying members of Congress have been briefed on the implementation of the surveillance programs, that they target foreigners located overseas for a valid foreign intelligence purpose, and that the programs cannot be used to target Americans anywhere in the world.
Intelligence officials said they are working to declassify information on the dozens of plots National Security Agency chief Gen. Keith Alexander said were disrupted, to show Americans the value of the programs. But they want to make sure they don't inadvertently reveal parts of the U.S. counterterrorism plans in the process.
The officials said both NSA programs are reviewed every 90 days by the secret court authorized by the Foreign Intelligence Surveillance Act. Under the program, the data, showing things like time and length of calls, can only be examined for suspected connections to terrorism.
They also said that all data gathered is destroyed every five years.
Some information for this report was provided by AP and Reuters.