[Mookster]

There are quite a few different contexts you could take this under. In tandem with the video that Intigir posted (and the general opinion he seems to have about the government being self serving,) I'd stand to reason that he means the government needs to be afraid that the people will not allow them to (for example) be self serving, threaten the senate into passing bills that are just plain ludicrous, and engage in fake wars.
I'd be afraid too, if the average person had half a brain, but the government really doesn't seem to have all that much to worry about. People are too busy waving flags to stop and think that they might just be becoming the new world enemy, or that their government might be serving a select few of it's own whilst condemning the rest of the States to what may be an economical meltdown or worse. And even if by chance you're wrong, you should still stop and consider the possibility. Americans don't though, and that kind of ignorance can come at a huge cost (nevermind the trillion dollars.)
The people within the government who actually can commit those war crimes should be afraid that the American people would not sit idly by and watch them **** **** up. If they have nothing to fear, they could do whatever the **** they wanted, and that seems to be exactly what they're doing. I think one could define that as tyranny.