The repeated rape of the US taxpayer by the IRS

The IRS is about to disobey Obama's directive NOT to issue union-negotiated bonuses in the amount of $70million.

I have a couple of questions about this:

-How is it legal for government unions to extort lavish salaries, benefits, and bonuses from the taxpayers from whom they take money at the point of a gun?
-Why are government employees unionized in the first place?
-Why do government employees even get performance bonuses? Have you been to the DMV or the post office? What exactly are they doing to earn bonuses?
-What are "union-negotiated bonuses"? Bonuses are a foregone conclusion? In what bizarro world do you get a bonus BEFORE the exemplary work is done?

This is infuriating! Bonuses? For what?