An artist has created what he's calling the "surveillance spaulding", a small piece of "armor" with an IR detector in it designed to detect surveillance cameras. Which obviously will only work if the camera: A.) Has an IR illuminator, and B.) it's turned on, and C.) it's in the right wavelength. When it detects IR, it makes the wearer's shoulder twitch via small electrical shocks.
I get that this is a design project and not a serious product, but it ranks as one of the silliest things I've ever seen related to surveillance.