He went to jail for creating a website that enabled people to download music and movies without paying for them. Jail is a harsh punishment IMO for that. ACTA/SOPA etc. are all terrible things that we can't allow and we can't allow the internet to become more centralised/controlled by government. But that's not why he went to jail. Enabling illegal downloads of content has little to do with those causes.
And what's the alternative ? The world is not the United States, in most countries of the world, there is simply no legal way to get a movie/tv show on the Internet. I'm not even talking about 3rd world countries here, Netflix (the only service which is good enough to compare to Torrents) just barely arrived in Europe and their list of movies is so poor, it's not even worth talking about it. Torrents are not working…
Plus some countries made it legal to make copy for personal use... and so on.