Telephone records can reveal a variety of private personal information including on personal relationships, political and religious affiliations and family medical issues, the senators wrote in their letter to Clapper. The collection of cell phone location data would effectively convert cell phones into tracking devices, the senators added. "We are concerned that officials have told the press that the collection of this location data is currently authorized," according to the letter.
The senators have also attempted to fill other gaps in their information on the government's secret surveillance programs, including asking for information on specific instances where the review of bulk phone records collected under section 215 of the Patriot Act has helped thwart a particular terrorist plot, which is a key justification the government uses for surveillance.
The Patriot Act's business records authority is broad in scope, and can be used to collect information on credit card purchases, pharmacy records, library records, firearm sales records, financial information and other sensitive data, according to the letter.
New legislation, introduced last week in the U.S. Senate, called the FISA Accountability and Privacy Protection Act of 2013, aims to reform the Patriot and FISA Amendments Acts to provide greater oversight and control to the government's surveillance programs.