I was once sat in the bog at one of the schools in York University when the lights went out. No amount of hand waving would turn it back on because the movement sensor was in the main area, not inside the cubicles. Luckily the "emergency" lighting was just bright enough to see by. Maybe if I'd not had a curry the night before I'd have made it out before the lights went off.
Biting the hand that feeds IT
