Today I didn't really need to count them, because every one of you is carrying one in your pocket in your cellphone. There are cameras that are so small that you wouldn't know.... I was just looking around this room wondering how hard it would be for someone to hide a camera in here.
We see that at DEF CON all the time. People put in surreptitious devices, not just cameras but even things that pick up your Wi-Fi. They'll leave them at the Starbucks and they can sit there for months transmitting all the data.
So yes, we are in a surveillance society.