It's amazing what engineers are willing to try before actually talking to someone ;)

In my apt. building the home control system is absurdally easy to hack - literally anyone can hijack their neighbour's light&ac control system via WiFi.

A friend of mine just shuts down lights of their neighbor when they make too much noise after midnight. I was close to doing the same when our neighbors were too loud, but decided on just going there and talking to them :)

I was really shocked myself. I guess I got to my senses when I started studying for radio license and made a very expensive list of radio equipment that I couldn't otherwise use because I live in an apartment building (antennas and all that) and even if it worked I would get into problems with the police for emitting above legal power limits.