Protests aside, my understanding is that there are plenty of circling flight paths available on Flightradar24.com in many major metropolitan areas of the US. I have personally seen (and heard) non-military helicopters flying near or above my house that do not seem to appear on the radar websites. (I check frequently.) I assume this is because their transponder is turned off. My understanding from reading articles is that these are usually FBI or Department of Homeland Security helicopters. (I can recall in one instance checking FlightRadar24 on a helicopter above my neighborhood and it was identified as "Federal Bureau of Investigation" so cloaking is not a universal policy.) It would not surprise me that these flights are raking in mobile phone information, perhaps while doing other things. This has been going on for years on a routine basis.
Then there are the local police helicopters that seem to come overhead daily, though I have to say it appears to be more often at night, sometimes transiting to get to other areas, sometimes just "trolling" around looking for trouble. Their flight pattern usually indicates that they will circle certain locations for 5-10 minutes then move on. I have not attempted to correlate this activity with land-based police activity that might be occurring at the same time.
Topic: Electronic surveillance of protesters (Read 1846 times)