The parties on the receiving end of these things are not generally informed of the details in advance, so they can hardly be said to have consented. In addition, the perpetrators use a combination of strong peer pressure, illegal serving of alcohol to underage pledges, and often physical force, to discourage anyone from backing out after they find out what's really going to happen. When these things get reported and prosecuted, it's usually either because one of the unwilling victims blows the whistle, or because something goes horribly wrong and somebody ends up in the hospital or dead.
Ambiguity may be part of any contract.
"In addition, the perpetrators use a combination of strong peer pressure,"
Legal. Commendable in some ways- the very point of such bonding related to any team spirit or conscription to service.
"illegal serving of alcohol to underage pledges,"
I fully support this as a libertarian, though good judgement dictates not actually doing so.
"and often physical force,"
I believe a perceived threat of physical force exists, but that it is real and used often... I disagree.
"to discourage anyone from backing out after they find out what's really going to happen."
False imprisonment is already a crime, considered next to kidnapping. That should always be prosecuted when it occurs.
"When these things get reported and prosecuted, it's usually either because one of the unwilling victims blows the whistle, or because something goes horribly wrong and somebody ends up in the hospital or dead."
So far, I have been argumentative in the interest of defending the right to haze and be hazed. It so happens on a personal level that I agree with you, largely. Hazing goes too far and gets out of control, and then ends up killing someone.
I support addressing the problem in some manner, but summarily banning an activity is not the American way.