At a jam a few years back, before the smoking ban, a friend was up using my back line. I usually go to the stage, between bass players, to help with the lead, EQ, tuning pedal etc. So I walked up to the amp to find a lighted cigarette on the side of the cab! It hadn't burned down far enough to cause any damage, but that’s what you can get when other people, even friends, use your gear!!!