An AP investigation has forced the FBI to admit that it uses at least 13 dummy corporations with planes like the one shown above to fly low-and-slow aerial spy missions over U.S. cities, capturing video and sometimes cellular signals from 30 cities in 11 states in a recent month.

Last week, we told you about the Department of Homeland Security’s “fusion center” in Baltimore and its ability to spy on Baltimore during the city’s unrest. But where would it get its info? Thanks to a few enterprising Twitter users, we have one possible answer: nondescript spy planes circling the city.