Hillary: The Movie
This 2008 film violated the Bipartisan Campaign Reform Act, which prevented any piece of "slanderous" media (whether it's funded by the opposition or not) to be released within an individual's campaign tenure. The Republican party viewed this movie as propaganda, because it actually reflected Hillary in a positive light, despite Hillary's opposition to the film's release. This law was reviewed and amended in 2010, two years after it was finalized, but the film never came out in a broad sense.
The Yes Men Fix the World
This HBO documentary follows two con-artists who infiltrate political spheres and masquerade as powerful businessmen to expose and mock exploiters of the lower class. The documentary was blocked from its release in 2010 due to lawsuits that were being filed against Andy Bichlbaum and Mike Bonnano (the film's creators). The movie ended up getting "leaked" and those who were filing the lawsuits were exposed for being unjust, greedy corporate scumbags that went out of their way to harm innocent people for a quick buck.