I was reading about the guy who forced some boys to flog themselves: http://news.bbc.co.uk/1/hi/england/manchester/7634275.stm
Whilst I can understand that people have a right to self-expression, I think we have to be very careful when it comes to self-harm, which is what this was. It sounds from what I read that the mosque got it about right, banning under 16's from taking part in the ceremony. Or at least in the rules they had in place... I'm not impressed that the authorities didn't police their own rules properly. I'm also unhappy that the rule is under 16, and not under 18. If you are too young to vote, drink, or buy cigarettes then you are far too young to be encouraged to self-harm (if anyone ever should be).
What this case does show very well is the problem of informed consent, peer pressure, and the ability to police rules in that environment. Sometimes it is better to infringe on a person's right to self-expression than to allow abuses of power that cannot be adequately policed and prosecuted. It's the same problem as with arranged marriages, there is nothing wrong at all with people choosing their partners with the help of others, it's how you police and prosecute the abuses possible in that system that again is the problem.
Sometimes to prevent the wrongs, you have to limit the rights.