Seems I heard a week or so ago a news report of some kids who were into the ninja stuff, jumping from roof to roof, running thru back yards, etc. They kept it up for a few weeks and got more and more into it and evolved into ninja burglars.
Eventually they cut it too close and somebody chased them out of his house. One of them jumped from the roof and landed wrong... he limped away and his parents took him into the emergency room to see if his leg was broken. The cops questioned him and his whole fantasy fell apart.