Edit: Okay, I just read Mohammad_Mahdi's post [#21]. It is haram to cut oneself, yes. But he goes on to say this:
So I don't understand. Are you against the practise period? Or only the people who take off their shirts and make themselves bleed?
Islamically, it is forbidden to hurt yourself, and it is certainly forbidden to hurt other people (i have seen some parents cut their kids).
There are 2 ways to explain this point:
1) people who do cut themselves/make themselves bleed are trying to bring forward an idea that they love the Imam so much, they want to hurt like he hurt. My beleif is, if you love the Imam so much, then you would follow his teachigs down to the tee. Thus, if such a person memorised the whole Quran, includin understanding it's tafseer (interpretation), and implemented the Quran perfectly in their lives without comitting a single sin, STILL had so much love and fire in their hearts that they cut themselves or whip themselves to their heart's content, then i would say i cannot hold much against such a love. That said, i feel that 0.0000001% of the population who perform cutting fit such a bill, so it's safe to say there are usually alerior motives behind the cutting
2) there is no proof in Islamic history (that i am aware of) that hurtin one's self to the point of bleeding, was done or if it was done was religiously accepted. When Prophet Jacob knew his son Joseph was missing, he cried to the point of blindness, but the Quran never mentioned him hurtin himself. greif with tears is accepted, and in fact from Jacob's story, recommended.
My personal opinion is that performing an action that will hurt one's self (like cutting/whipping), is forbidden. My view is that people who do this either a) are attention seekers (ask them to recite one of the shorter chapters of the Quran by heart, i'd be surprised if they memorised it) or sometimes are not even from the school of thought, and infiltrate such gatherings to perform actions that'll taint the picture of Islam.
Again i go back to the point i made in my first post. We should not be extremist in any views. We have to practice tolerance in other people's beliefs, as long as those beleifs don't hurt other people (like a father cutting his son, that must be stopped). And when we talk to people of opposin views, we should adopt the Quranic principle "and debate them with wisdom and GOOD exortation"... the Quran mentions good exortation, and not just any exortation.
And Allah (SWT) knows best