It's a very disconcerting event that needs to be stopped, IMO.
I don't believe their “excuse” and I'm of the opinion it was an exercise in “control”.
It happened a couple of times where I lived in Orange County, CA. The helicopters are incredibly loud when they hover near the ground, and their loudspeakers are even louder. The blinding searchlights add a memorable effect.
Both times the cops were looking for a guy who just broke into the nearby supermarket.
The first time we lived in (San Marino) California we were scared of the helicopters flying over our house, circling around and around. Scared us to death. We assumed it was a bad guy running from cops, and it may have been. After living in L.A. area five times since 1988, helicopters flying overhead no longer scare us. But it is so strange the first time or two!
Don’t feel lonely. We have the choppers circling our neighborhood on a regular basis. At least once or twice a week. Sometimes in the middle of the night.