What's to keep our government from using the same technology via the media?  Now that televisions operate on digital signals, how do we really know what we're looking at isn't touched up, edited, or otherwise falsified?  Answer is:  you can't.

Are you saying that the DNC inserted all those hordes of people at Obama rallies to give the impression that the masses were behind him when they were not??  ;D

Why not? The Russians were masters at this before digital (wish I'd picked it up) according to a book I looked over when I was teaching photo.