Law enforcement agencies’ acquisition of drones has raised concerns about their use to monitor protests. Unlike helicopters, which are also used to monitor protests, drones are more affordable and can fly in closer to demonstrations. They are able to hover above crowds, not only to take pictures but also to record video and audio clips of protesters. The data that drones capture can be coupled with facial recognition software to allow police to identify large numbers of individual protesters in real time.
As of 2017, eighteen states required law enforcement agencies to obtain search warrants before using drones for surveillance or searches. Vermont’s legislation explicitly bars law enforcement agencies from using drones to “gather or retain information on private citizens peacefully exercising their constitutional rights of free speech and assembly.” Most states, however, have not passed legislation to regulate the use of drones by law enforcement agencies during protests or at other times.
Illinois requires the police to obtain warrants before using drones for surveillance, but a billintroduced in 2018 would exempt drone surveillance of protests from this rule. The bill, which passed the Illinois House of Representatives but stalled in the Senate, was heavily criticized by civil liberties organizations, which warned that drones could be used to track and harass protesters and protest organizers.
Other aircraft equipped with camera technology can also be used to track protesters. In 2016, Bloomberg reported that the company Persistent Surveillance Systems provided aircraft surveillance services to the police department in Baltimore and used a plane equipped with specialized cameras that circled the city for hours. The cameras covered approximately thirty square miles and transmitted continuous real-time images to analysts on the ground. Such technology, particularly combined with other surveillance practices, can be used to track protesters and, as a result, discourage participation in demonstrations.