They only point one direction.

I was at a town hall meeting for the little town I live in. There was a line item to discuss the installation of a flock camera. A quip rang out from the crowd when it was mentioned: “Have you seen a stop sign without a bullet hole in it in the area? Do you think that camera would somehow not be shot?”

Pole shortener. Can pick them up at any hardware store.

Do they have to be autonomous? Because your idea sounds fun.