A federal judge in Madison, Wisconsin ruled that the IRS's claim didn't belong in federal court. Instead, she ruled, the government needs to fight this matter in the state court overseeing Ambac's reorganization.

How worried is the IRS that Ambac will spend a disputed $708 million "quickie refund" it received in Feb. 2010? So worried that it has taken the apparently unprecedented step of naming the Wisconsin state court that approved an Ambac restructuring plan as a defendant in a suit to enjoin Ambac from disbursing the money--even though the IRS hasn't even filed a formal claim to the $708 million.

The number of whistleblower suits against companies that mark their products with expired patents exploded over the last year-and-a-half. But the boom appears to be over.

In recent years, one of the reasons for the ballooning cost of patent litigation is defense claims that patent holders deceived the Patent and Trademark Office, and so their patents are invalid because of inequitable conduct. On Tuesday the appeals court said enough is enough and raised the bar for misconduct allegations.