According to the letter, a surveillance program now known as Data Analytical Services, or DAS, has for more than a decade allowed federal, state, and local law enforcement agencies to mine the details of Americans' calls, analyzing the phone records of countless people unsuspected of any crime, including victims.
The DAS program, formerly known as Hemisphere, is run in coordination with the telecom giant AT&T, which captures and conducts analysis of US call records for law enforcement agencies, from local police and sheriffs' departments to US customs offices and postal inspectors across the country, according to a White House memo reviewed by WIRED.
In a letter to US attorney general Merrick Garland on Sunday, Wyden wrote that he had 'serious concerns about the legality' of the DAS program, adding that 'troubling information' he'd received 'would justifiably outrage many Americans and other members of Congress'.