Although the government still hides too much information about a secret telephone records surveillance program known as Hemisphere, we have learned through EFF’s Freedom of Information Act (FOIA) lawsuits that police tout the massive database of private calls as “Google on Steroids."
Hemisphere, which AT&T operates on behalf of federal, state, and local law enforcement, contains trillions of domestic and international phone call records dating back to 1987. AT&T adds roughly four billion phone records to Hemisphere each day, including calls from non-AT&T customers that pass through the company’s switches.
The Drug Enforcement Agency (DEA) and other federal, state and local police use Hemisphere to not only track when and who someone is calling, but to perform complicated traffic analysis that can dynamically map people’s social networks and physical locations. This even includes knowing when someone changes their phone number.
And federal officials often do it without first getting permission from a judge.