This WashPost article is scary. Very scary.
As Benjamin Shayne settled into his back yard to listen to the Orioles game on the radio Saturday night, he noticed a small plane looping low and tight over West Baltimore — almost exactly above where rioting had erupted several days earlier, in the aftermath of the death of a black man, Freddie Gray, injured in police custody.
The plane appeared to be a small Cessna, but little else was clear. The sun had already set, making traditional visual surveillance difficult. So, perplexed, Shayne tweeted: “Anyone know who has been flying the light plane in circles above the city for the last few nights?”
. . .
What Shayne’s online rumination helped unveil was a previously secret, multi-day campaign of overhead surveillance by city and federal authorities during a period of historic political protest and unrest.
Turns out the Baltimore police had requested the FBI conduct aerial surveillance of areas where demonstrations were being held. The surveillance was conducted by two FBI aircraft flying precise orbits over West Baltimore.