Why is this so funny?

This video is disturbing. Mostly because I'm upset by the fact that I can't stop laughing at something this idiotic. On paper, this one-note stunt is not only incredibly pointless and dumb, it's dangerous. New Yorkers aren't famous for being touchy-feely, especially ones attempting to hail a cab in the middle of the day. If the video becomes a hit and this bearded knucklehead attempts a follow-up, there's a decent chance he'll get seriously hurt. If he happens to slap the wrong guy running late to catch a flight... well, let's just hope that doesn't happen.

Sources: Tastefully Offensive