Back in the 90s a friend had modified his Realistic brand radio scanner to pick up cell phone frequencies. Nothing was encrypted back then. One of the calls we heard was of a computer generated voice repeating the phone number, the "internal temperature" and then a thirty second audio feed of what sounded like machinery. Every time I tried calling the number, it was the same thing though the temperature varied by a couple of degrees now and then. Never heard any voices or much variety in the machine noises. No idea what it was other than some local factory.

The condo building I lived in during the 2000s had its server with all of the video cameras hacked. Probably the most exciting thing anyone could see was the fitness room with people exercising. We had no idea if anyone actually bothered watching the feeds or if it was just part of a botnet.