The figures included responses to both federal and local police requests.
“The expansive nature of these information requests likely results in the collection of sensitive records of innocent consumers by law enforcement,” Markey wrote in his letter to the Justice Department. “The practices of law enforcement agencies, along with the enormous amount of requests, range of information provided, and large numbers of consumers involved, raise a number of important privacy concerns. It is important to know how law enforcement is handling the records of consumers, especially those who are innocent, which may be collected as part of these information requests.”
Sen. Al Franken (D-Minn.) sent a similar letter to the Justice Department in May, asking for details about the department's collection of cellphone location data. Holder responded in June, saying the agency does not keep records on the total number of requests for location information.
"The Department has a lot of questions to answer—and it’s clear we must do more to strike the right balance between the needs of law enforcement and privacy," Franken said in a statement on Wednesday.