Why would the United States government attack its own citizens?

[fredtoast]

I ahev always heard theories and conspiracies about how the Government is planning to imprison most of the common citizens. That part I can never figure out is what they would have to gain from doing that. Isn't it a lot oft trouble to lock everyone up and have to feed them and guard them and all of that? Who would pay for that and what would they have to gain to make it worth their money and trouble?

Also how do they get the military personnel to all turn against their fellow citizens? That part doesn't make sense to me either.

I know this is a very popular theory, especially among people who make their living selling guns. But can anyone explain why it would make any sense for the government to do this? And how to they get all the enlisted men to go along with it?