It started when visitors to the White House website started noticing that the Bush administration were deleting and editing speeches, audio, and video from the White House website which could be seen as either contradicting other Bush statements or potentially embarassing to the Bush administration. Truely Orwellian.
Well, now it has gotten worse. For the first time, transcripts of the President's speeches feature the audience saying things such as "Four more years! Four more years! Four more years!" and "Booo!"
With that in mind, you have to wonder how long it will be before they start using audience "plants", placards, or teleprompters to drive the audience response at poliical events... Josef Goebbels would be proud!