At EFF we spend a lot of time thinking about the tech used by police and authorities to spy on you while you’re going about your everyday life, like cell-site simulators (CSS). Rayhunter is an open source tool we’ve created that we hope empowers everyone to help search out CSS around the world. https://www.eff.org/deeplinks/2025/03/meet-rayhunter-new-open-source-tool-eff-detect-cellular-spying