Last night, I had a bit of a situation. It was a great gig overall, but here's what happened:
About an hour into the night, some idiot jumped onto my sub to dance away. What I assume to be his missus was trying to get him down and my roadie rushed over to do the same. I was half way through a mix so I hadn't noticed immediately what was going on but when I did, I dumped the mix, took my headphones off, walked over and shoved him off. He went crashing to the floor and got covered in the contents of his own pint. His (I assume) missus had a look of shock on her face, but he was so drunk that he just didn't understand what happened. I then got on the mic, stopped the music and said straight to him "If you pull that again, I will stop the music completely, pack my stuff away and you can explain to the bride and groom why their wedding day has ended early!"
He was off with his tail between his legs and I never saw him anywhere near the booth again for the rest of the night. From that point, music continued as if nothing had happened.
Now, whether I was right or wrong to just shove the guy off is in the eye of the beholder. In my opinion, he had ample opportunity to get off before I came over (completely bypassing the fact that he shouldn't have gotten on it anyway). But it did make me wonder that even though we never want to be in a situation where we have to protect either ourselves or our kit, but at what point do you consider it reasonable to use proportionate force to do just that?