Understanding if CSS are being used to spy on protests is one of the main goals of the Rayhunter project. Thanks to members of our community bringing Rayhunter to dozens of protests, we are starting to get a picture of how CSS are currently being used in the US. So far Rayhunter has not turned up any evidence of cell-site simulators being used to spy on protests in the US — though we have found them in use elsewhere.
Rayhunter users have detected likely CSS use in the US as well. We have received reports from Chicago and New York where our “IMSI Sent without authentication” signature was triggered multiple times over the course of a couple hours and then stopped. Neither report was in the vicinity of a protest. We feel fairly confident that these reports are indicative of a CSS being present, though we don’t have any secondary evidence to back them up.
We encourage people to keep using Rayhunter and continue bringing it to protests. Law enforcement trends can change over time and it is possible that some cities are using them more often than others (for example Fontana, California reportedly used their CSS over 300 times in two years). We also know that ICE still uses CSS and has recently renewed their contracts. Interestingly, in January, the FBI requested a warrant from the Foreign Intelligence Surveillance Court to use what was likely a CSS and was rejected. This was the first time the FBI has sought a warrant to use a CSS using the Foreign Intelligence Surveillance Act since 2015, when the Justice Department began requiring a warrant for their use. If police start using CSS to spy on protests we want to know.