Supreme Court shoots down two more rules put in place by top patent court

The US Supreme Court issued rulings in two of the five patent cases it heard this term. In both cases, the high court unanimously struck down rules created by the US Court of Appeals for the Federal Circuit, the nation's top patent court.

The two rulings continue a pattern that has developed over the past several years, in which the Supreme Court has overturned key Federal Circuit rulings, finding them too favorable to patent-holders and too harsh on parties accused of infringement. All four of the companies involved in the legal opinion are competitors with real products -- none represent the much-debated "patent trolls," that is, companies with no business beyond patent lawsuits. Yet, the issue of patent trolls looms large in the background of these opinions.

Both decisions will make life easier for Internet and other tech companies frequently accused of infringement.

In the case of Limelight Networks v. Akamai Technologies, trolls were happy to use the Federal Circuit-approved theory about "induced infringement" to sue tech companies. They argued that even when a defendant didn't complete all steps of a patent itself, it encouraged its customers to do so. In the case of Nautilus v. Biosig Instruments, the Supreme Court has made it easier to throw out patents on the grounds that they're "indefinite." The ruling widens another path of attack that can be used against vague patents.