Allright, this happened to me yesterday; My band had a gig, one of 5 bands and we had the sweet spot as band number three to go on. We had a great time and did a good gig, with a good crowd in front. So far, Great! We play Zeppelin-ish rock, and our leadguitarist played in a blackmetal-band, lets call them Zuge, a couple of years ago, and they planned a reunion gig, and were to go on stage right after we went off. So, we go off, and Zuge go on. I go to the backstage-area and pack down my instrument, a brand new winered Yamaha BB414. Then I go out to the stage to look at the show. Suddenly Zuge's bassist proclaims on the PA "My bass isnt working!", and then he jumps of stage, only to come back to stage with MY BASS. Had he asked me? No! He just stole it. Apparently I was the only one there with a bass. Not only did he take my instrument without asking me, he went on a total rampage on stage, smashing in to everything, and denting my precious instrument. I decided to play it cool and see what happened, as I hoped that he would just smash the neck or something and would have to buy me a new one, and AT THE TIME, I felt going on stage and ruining the reunion-show that my friend (leadguitarist in our band) had looked forward to, would just've made me an ass in front of the crowd. I ofcourse regret not doing this today. After the show, he came backstage, and said: Him: "Hey, I borrowed your bass" Me: "Yeah, what the ¤%#" man?! You cant just steal an instrument!" Him: "yeah well you werent here." At NO time did this SOB show any respect, he just talked as if it was the most natural thing in the world that he had just stolen my bass and dented it. He left the backstage-room, and I found him outside 5 minutes later hanging out with his fellow BM'ers. Ofcourse we started arguing, and were about an inch from a fistfight (Which I tried to avoid, because some important booking-guys stood behind us). That stupid ¤%#"¤% couldnt understand why I was so pissed about him stealing my bass. Apparently the bassist had asked my friend if he could borrow my bass, and my friend apparently said yes. Ofcourse, my friend has no recollection of this at all. I told him that it's a matter of principle, that you at no point gig with another persons instrument without asking, and WHEN YOU DO, you treat the instrument with the utmost respect, not like a POS-bass that you can smash all around the stage. So, what would you have done? If he had just apologised when I first saw him backstage, I would've let that be it. But he acted like the most arrogant #¤%&¤# I've ever met.