As somebody who builds websites and web content for other people I’ve needed to educate myself on what is and what is not a copyright violation, or what is fair use and what is not. I’ve also worked with people who have created documentaries, so my statement that “SOPA” censors history is a bit of hyperbole … current copyright laws censor it. All of the interviews done by the company I worked for they hold the copyright. However, the problem is not limited to recent history. Many of the people who were interviewed are now dead, as is Martin Luther King. These interviews can not legally be used without expressed written permission.
Fair use is a topic I have always avoided posting about because what is fair use is what the judge says is fair use. You can check with attorney after attorney, the law is open very open to interruption by a judge on a case by case basis. So much so that many films avoid having any product that is trade marked appear in their movies. A cease and desist order means the movie would need to be pulled have that part of the film changed.
However under current law the person who wants to claim fair use can present his case to the judge. There must be a legal basis for a fair use defence, not merely that you wanted to use it. A defence can be to comment on the work, Criticism of the work, or parody. http://fairuse.stanford.edu/Copyright_and_Fair_Use_Overview/chapter9/index.html There is also a fair use for education.
I would ask an attorney, about the education usage of fair use, before attempting to use an interview in a new documentary under fair use, and because the only video or tape of the speech is copyrighted, (can not be recreated because person is dead). If you get an attorney to represent you then follow his direction.
What will change under SOPA/PIPA is you don’t get your day in court unless you take the person who filed a claim to court after your site was taken down. You don’t get re-compensated if the claim is completely bogus or if your usage is fair use.