Plenty of times my friend....
eg. the time when this guy threw a ball at my head (deliberatly) and I decided not to let it go (caught me at a bad time), he stood their talking to me like he was god so I knocked the ball out of his hand to make him look like an idiot (dont think he liked that
), he then grabbed my sleeve, without thinking I put my hand on top of his via inside and thrusted my fist in a downward/outward motion. I guess I kinda did it hard or he just did'nt expect it cause his arm flew behind him and he nearly span round, then some friends of mine ran over to us and started saying stuff like "you trying to start a fight with this guy? I woud'nt try it".
The matter ended and I went on as normal.