At university I spent a term doing lights for bands in the SU. One night a bloke in front of the desks turned round, looked me in the eye and pulled the power to the lighting desk before vanishing into the crowd. Fortunately the cable didn't disappear and it was only a few seconds before it was back in and being the days before digital desks, or at least, ones that the ENTS team could afford, it was only a minute of darkness.
The sound engineer and l, who fortunately for my reputation, if not my peace of mind, was the ENTS manager shared a "What an Arschlöche" look and had a beer over it later one. Probably nicked from the band, SU bands were usually generous to the crew with their riders! 😉