I don't what all you morons are talking about. The body hardening is legit. And also the self defense techniques with the older guys wearing regular clothes is spot on... Those are basic karate techiques. When I fight I never take it to the ground. A strong front kick and reverse punch is all I need.......
I do karate at a very good school, as well as BJJ, and I have to say that the only technique that was viable was the two fingers in the curvature of your collar bone, where you press your fingers down into the throat. That hurts like a mother f'er! But, I'd rather go with an elbow to the face.
However, all of the other techniques were utterly ridiculous. For example, the ball flurries would never work. In fact, my friend and I were watching the video and were making fun of it, and then I said, "Hey, I'm gonna choke you and you try to drop your weight down and do ball flurries on me." He dropped down, and you know what happened? It was like he was basically hanging himself. He made the choke tighter, so that's a good technique (sarcasm).
The Takedown from Glasses wasn't even a takedown, he just threw his glasses and then moved towards the guy and the guy fell down. The joint locks are ridiculous, because he could definitely get his arm around, he just didn't try. The locks do hurt, but you can't pull off a lock on someone who is not cooperating. You have to bend their arm all funky using both hands, all the while they have one hand free to pound you in the face with.
Also, the knee-on-belly sweep would never work unless the person you were facing was as thin as a piece of paper. Yes, the turning of the shoulders would break their grip, but the sweep part will not work.
It's a video of stupid techniques, and as someone else said, it's Nerd Jitsu.