Most of the whining about this is just about being able to look at your stuff. It doesn't mean that the government will look at what sites you visit, but it means that they can look at what sites you visit. My understanding is that it's like someone going into your home and looking at your history because they got a tip that you had child research. To my understanding, it's basically "if you're doing stupid stuff, the government can watch and promptly arrest you." What else does this do? Is it just that the government could possibly look at your history/chatlogs/whatever?
You seem to forget the fact that if they suspect you of illegal activities, even if you really aren't, they will confiscate and search through your personal files by literally taking any electronic equipment.
Downloading mp4s from YouTube? Won't happen with ACTA.
Burned a new mix CD for a friend? Won't happen if the songs were downloaded through YouTube or Limewire.
ACTA will severely restrict internet privacy.