For the record: things that ACTA allows and supports include, as part of their copyright infringment provisions, a near abolishment of the principals of fair-use.... not mandatory, of course, but it allows it, and facillitates it. If read int he spirit in which it is intended ot eb red, then ACTA is a good thing, and seems fine... but read it carefully and think about what it's actually allowing to be done, and you find the real problems.
Want to put up a Let's-Play on youtube? Someone Citing ACTA could have it taken down.
Want to to make a fan-vid tribute using songs and footage from your favourite subject/game/actor/character? Again, by ACTA, it can be counted as infringement and removed.
Want to publish a fan-fiction that you wrote on a fan-fiction or shrine site? ACTA has the power to deny that as well.
Worse, it's still in the form of Take Down Now, -maybe- ask questiosn and listen to appeals later... which is unfair to individual people.
WILL these things all defintiely happen and be enforced globally against individuals? Likely not... However, they CAN, and if they -are-, there's nothing any individual can do about it. That is the real problem, and the real injustice.
P.S.
http://en.wikipedia.org/wiki/Anti-Counterfeiting_Trade_Agreement
Have a read, and while there you can find some more comprehensive links to more detailed texts. If it is enacted, then we really do have a lot to be concerned about.