Never mind the old one.
When it comes to self-defense, what is ethically acceptable?
Is the defender allowed to take more than an eye for an eye?
Define horrible.
1 : marked by or conducive to horror
2 : extremely unpleasant or disagreeable
like what’s happening to our friend spiderman there.
In that case, kill the bugger! I don’t know if Spider-man will ever walk upright again. 
Although I’ve seen that picture before, and the worst part is that CF didn’t alter it. The cover of a real comic looks like that!
getting back to the topic though…
it depends where you are. in my school, for instance, if someone punches you in the face, both of you get expelled, even if you don’t fight back.
Well, by that logic it seems that if you get punched you might as well fight back. If you get expelled you should deserve it.
yeah, that’s basically what happens. it’s really not quite the deterrent they want it to be. (being overly strict, that is)
I think it really depends upon your opponent, if you are significantly larger and stronger or have more fighting knowledge then your opponent, you need to show restraint. Kind of like a golfing or bowling handicap. Of course if you are the puny one I suggest putting it in reverse and making distance.