To quote the youtube uploader's description

This is from a martial arts demonstration on board the USS John C. Stennis in 2002. At the time I had only been studying Judo for about six months the ninja claimed 27 years experience in martial arts. We had not practiced a routine for the demo nor did he give us any instruction as to what techniques were to be performed. After talking about the principles of his style he had me and another person attack him. This is what happened.

I'm the one applying the choke.

For those who have problem with the audio the following is the ninja's statement after getting the choke on him.

"See the bad thing about somebody who does judo...Once they got to the ground they can't do anything. So I just relax. Piece of cake. Okay hold me there all you want. What are going to do?" to which someone in the audience yells out "Choke your ass!!"