The head of the National Security Agency has admitted to secret pilot programs to monitor the precise location of Americans through their cellphones, saying the highly intrusive tracking data "may be something that is a future requirement for the country".
General Keith Alexander, the director of the NSA, said that the pilot programs from 2010 and 2011 were intended to test the compatibility of the location data with the agency's databases, but were not used for any intelligence analysis purposes.
However, giving evidence to the Senate judiciary committee on Wednesday, Alexander left little doubt that the NSA was interested in a potential dragnet of location data, which would constitute a significant extension of its surveillance powers.
Last week, before another Senate committee, Alexander evaded questions about whether the NSA had ever collected information from cellphone towers, which helps pinpoint an individual's movement, suggesting the information might be classified.
Asked on Wednesday by Republican senator Ted Cruz whether the NSA would ever seek location data of Americans to combat terrorism, Alexander said that would be a possibility, but that the agency currently obtains the information on a case-by-case basis.