Law enforcement agencies have used aircraft for decades to conduct surveillance, but modern radio, camera, and electronics technology has dramatically expanded the power and scope of police surveillance capabilities. The Iraq War and other conflicts have spurred the development of mass surveillance technologies and techniques that are now widely available to domestic police. The FBI, DEA, and other agencies flew powerful surveillance aircraft over cities for years in relative secrecy before breaking in to public attention in 2015. This presentation will discuss the capabilities of these aircraft, the discovery of the FBI and others' surveillance fleets, and continued efforts to shed light on aerial surveillance. We will discuss a method for detecting surveillance indicators in real time based on mutilateration of aggregated ADS-B data, and introduce code for detecting surveillance indicators from flight behavior.