Well it's no surprise this is happening. It's not all about Copyright. Copyright is also another tool to censor media incriminating to the US government from reaching an audience in which it will have a profound impact...the American tax payers and voters , as well as a global audience.
Youtube has enough credible evidence and investigative documentary's about 911 (amongst the crap of course) to warrant a new independent investigation. This will not be allowed to happen. For example, the work of Architects and Engineers for 911 truth.
Uploaded on Youtube are documentary's by real Journalists like John pilger and Robert Fisk whom expose Misconduct and brutality by the US military as well as the crusader and expansionist aspirations of right wing US politicians, Zionists and the Israeli government, (the same group of people that engineered the Iraq war and are trying to lay a bum rap on Iran). Censoring youtube is of high priority because of how wide an audience can be reached as opposed to obscure websites in dark corners of the internet.
Imagine if the US public knew more about the ethnic cleansing of Palestine and simultaneous birth of Israel and continued oppression and brutality toward the Palestinians. Or perhaps zionist terrorist acts like the Bombing of the King David hotel whilst dressed as Arabs, or the Lavon Affair, or the Attack on the USS Liberty in an attempt to fool the US in to attacking Egypt, or how about the Mossad operatives caught on 911 with vans full of explosives, later released back to Israel on immigration violation charges. Or the power of AIPAC a foreign agent in the US... How many Americans bar the Christian zionists, will allow their tax dollars to be given to Israel, whom cannot survive economically without it?.
We have also seen the power of the internet with the "Arab spring" protest and revolutions as well as the occupy movement. This is just to scary for our keepers, hence Sopa is the beginning of the end. It's ok we will just have to take it to the streets.