In early 2006, "USA Today" reported that several major telephone companies were providing the telephone call records of U.S. citizens to the National Security Agency (NSA), which is storing them in a large database known as the NSA call database. This report came on the heels of allegations that the U.S. government had been conducting electronic surveillance of domestic telephone calls without warrants. In 2013, the existence of the Hemisphere Project, through which AT&T provides telephone call data to federal agencies, became publicly known.