Forcing them to pay, even when it was later proven that they are not the actual father. Not allow them to check, if they are actually the father without the mother's approval. And on top of that, follow the mother's choice in case she doesn't want the father (or "father") to see his child. And also: if the couple separates later on, the mother gets custody in most cases. Everything about it is pro-mother and "fuck you" to father.
Oh and in case you aren't married to the mother, she may even give away your child to adoption without your approval.
http://www.babyemmawyatt.com/Articles.html I think that's also a big fuck you to fathers.
You could argue that all of this is okay, because well the mother got the child and the father didn't. And yes, that's probably right. But all of this is also punishment for sex, which you asked for.