It affects all of the content shared on the Internet through American providers, so it affects a large portion of the Internet for all countries.
Well, the EU has the same thing going on. Finlands second biggest ISP already had to block access to piratebay.
I don't understand why anybody would even want to fight piracy, unless it's for money. So I have no ethical problems on beind a pirate myself. Besides the ethical part, those same huge companies have forced (?) such piracy taxes that I think are pure idiocy. Well, there is a tax on VHS/CDs for a long time. Because they assume you are going to put illegal material in there! I don't know if already applied or still in discussion, but the same is for 'modern' multimedia storage devices - ipods, mp3 players, dvd players, so on.
This is all just for money. Huge companies = profit. Of course they claim that piracy is bad and have to fight it. But I don't think huge companies are poor... Just creedy.