The FBI's internal guide for getting data from AT&T, T-Mobile, Verizon

Much of the information reiterates what we already knew about law enforcement access to telecommunications data-how officials can request location data from a telecom with a warrant or use court orders to obtain other information on a phone user, for example. The document does provide insights on what exactly each carrier collects, a more recent run-down of how long each telecom retains certain types of data for, and images of the tool the FBI makes available to law enforcement agencies across the country to analyze cell phone tower data. CAST supports the FBI as well as state, local, and tribal law enforcement investigations through the analysis of call data and tower information, the presentation adds. CAST provides its own cell phone data visualization tool to law enforcement officials around the country called CASTViz for free. The document also explains how data requests from Mobile Virtual Network Operators such as Boost Mobile are handled, explains how to obtain location data from what the FBI describes as "Burner phones," and how to obtain information from OnStar, General Motors' in-vehicle system. AT&T holds onto data such as call records, cell site, and tower dumps for 7 years. A screenshot from the document providing an overview of different data retention periods.