Maybe you should ask those guys in the NFL with the super long hair hanging out of their helmets. I am amazed people like Troy Polamalu don't get their hair ripped out all the time.
Oh, no. I mean, I know that the NFL officially made hair part of the uniform and thus legal to grab, but I've never seen it happen, and I have to believe there's a reason for it...and, just a guess that it's the obvious reason: pull someone's hair and they're likely to lay you a lick. It's a bad idea unless you really want to start a fight.