hey, even if they do ban parkour. what are they going to do? arrest us? Parkour is learning the most efficient path to get somewhere, we can out run the cops anyways. I really wouldn't be too worried about it until someone does try to ban it.
Then you would have the adtional charge of resisting arrest, and the use of non leathel wepons is on the rise in PD's and Sheriff's deparments, the best example of which is the taser.
Think about it, it would only give Parkour a worse rep if you did that.