Is the tax rebate a ploy to find out who hasn't been filing?

So people who would normally not file because they would owe a balance due are going to file solely to get the $600 stimulus payment? That means they must owe less than $600 or they wouldn't file, because they would still have a balance due. So for you theory to work Congress must have decided to pay $600 to everybody in order to flush out a few non-filers who owe less than $600 each? That hardly seems cost effective. That doesn't mean your theory is wrong. But if your theory is right, then Congress is collectively more inept than we imagined.

That is one of the things the government will use it for, since the idea of the rebate is to give you back the taxes you would have paid in during 2008. There are a lot of ways cheaters are caught. It is just that most cheating is not worth the IRS going after.