I have done security, body guarding and bounced for many years.

I have been in many situations that MA has came in handy.

I will say much of the fighting applications you learn cannot be used in these situations as you are more proned to subdue as green cloud said then to beat the person up or cause bodily harm. not as much fun, however a great story

I was bouncing at the VIP lounge in NY the old grants building on the 2nd floor. I had to break up a major fight. When i tried to escort the one gentleman out the door and down the marble stairs he kept trying to fight me. I had him in a wrist joint lock and was applying a great amount of pressure to which he didnt realize being so drunk or drugged up. Then after several warnings and to defend myself or course I accidentally snapped his radius bone.

When this happened he freaked out, lost his balance and fell down 35 marble stairs, rolled over 2 other guys and hit the door at the bottom with his head and shattered the glass

I got sued and fired the next day.