A new report suggests that telecom giant AT&T spied on its customers in exchange for government cash. The company is believed to be running Project Hemisphere, which allows for warrantless surveillance.

The project was first reported in 2013 by the New York Times. However, at that time, it was assumed to have only been used in a couple of states for specialized anti-drug operations.

According to The Daily Beast, Hemisphere is a secretive program which can trawl through trillions of call records. It can also analyze cellular data to determine the location of a target and their communication with other people. The project was allegedly "developed, marketed, and sold at a cost of millions of dollars per year to taxpayers."

The program has been condemned widely by various digital rights activist groups. According to Fight for the Future, the program goes beyond the pale of government surveillance revealed by Edward Snowden. The group said that AT&T not just complied with government requests, but built a powerful product for selling private information to government agencies. The digital rights group said that such "for profit" spying is a danger to the US democracy.

It is believed that authorities paid between $100,000 to millions of dollars to access data from Project Hemisphere. Such requests only required an administrative subpoena.

AT&T has issued a statement in response to the controversy stating that communication companies are under legal obligation to provide non-content information whenever required by a government agency through a subpoena or other legal process. Meanwhile, digital rights groups have called for the shutdown of the program.