There are these random USB ports on the wall in my school. They all seem to be placed by a door or emergency exit and nothing is plugged into any of them. I plugged my USB power bank into one of them and it started charging, so these ports are connected to something somewhere. I originally posted this on Reddit a few weeks ago but nobody could give a clear explanation. Maybe some of the alarm-geeks here could figure this one out?
-Calvin :TBolt: