They are not our laws. They were forced upon us by a combination of US government pressure and outright bribery. And they are now sending our people to prison and censoring our internet access for things we do not consider to be crimes.
The protest against ACTA is not so much a matter of "ACTA is evil", it's more a matter of "this corruption stops now".
We want our freedom an sovereignty back, not to have it signed away in some treaty, even if that treaty has been watered down to something merely symbolical with no immediate effect. It is patently obvious that they won't stop at ACTA in it's current form.
Sometimes that mere fact that you finally draw a line is more important than where exactly you draw it.