[calf]

If you came upon a young man laughing and about rape a woman and the only way to stop him was to magically have his penis disintegrated with no repercussions would you?

Why leave it up to the law, which is far from foolproof, when not only can you punish the individual you can also prevent the crime for ever happening. Also if you're the only witness do you really want to deal with attempting to get the young men prosecuted? If they're minors then they hardly get in trouble at all, even though an 18 year old does not innately know better than a 17 year old.

I am also not that aware of animal cruelty laws in America but I am fairly sure that they are rather severe in a lot of cases. I seem to recall (though I'm not certain) a recent case in which a man got 10 years for some brutal torture/killing of a dog. I'm not sure these guys would get nearly that much time but it's not impossible. Is taking away a man's freedom for what should be 10 of the best and most productive years of his life really not comparable to lopping off his hand? Just because the provision isn't there in the law doesn't mean it isn't a reasonable reaction.