Probably not a reason for "low-flying, military-style helicopters" but... from a reader...
A bunch of hipster a**holes just walked up 1st Ave. honking atonally on saxophones and bassoons, like a flock of very loud obnoxious geese. They stopped at every storefront, bodega, bar, restaurant, and aimed their horns at the open doorways and honked and honked, making a noisy mess. 11:00 at night. WTF?
