Who's running this joint?

You've probably heard about the Istook Amendment. That's the name being given to the amendment to the current spending bill that would have let certain certain congressmen, their staffers, and pretty much anyone else they authorize to look at the tax returns of any American for any reason. Like the Democratic prosecutor that's trying to indict Tom Delay for breaking campaign finance laws. Hypothetically.

Talkingpointsmemo.com points out that it's been four days, and still, no one knows how that language got into the bill.