In this case the Supreme Court rejected efforts by EFF, Microsoft and others to make it easier to invalidate a patent.

Here’s some background: In court parties have to prove their case by some "standard of proof." In almost all civil cases the standard is "preponderance of the evidence" – meaning it is more likely than not that the facts are true. When the question is invalidating a patent, however, the U.S. Court of Appeals for the Federal Circuit decided that a defendant trying to prove a patent invalid must do so by a higher standard than normal civil cases that of "clear and convincing" evidence. "Clear and convincing" means that the facts are "highly probable " which is a much more difficult standard to meet than just a preponderance.

In this case i4i Ltd. had sued Microsoft for patent infringement. i4i claimed its patent covered editing documents that contain markup languages like XML (Microsoft Word had XML editing capabilities). Microsoft had argued that i4i’s patent was invalid because the disclosed invention had been embodied in a software product sold in the United States more than a year before the patent application was filed – prior art that the patent examiner did not consider. The Federal Circuit applied its clear and convincing standard and rejected Microsoft’s invalidity argument. Microsoft petitioned the Supreme Court for certiorari and was supported by eleven amicus briefs including EFF’s. That Court granted Microsoft’s request to decide whether the Federal Circuit’s standard of proof rule is correct. EFF then filed another amicus brief that asked the Supreme Court to overturn the Federal Circuit's rule.

Unfortunately, in a June 2011 decision, the Supreme Court upheld the Federal Circuit's rule that a patent may only be proven invalid by clear and convincing evidence. The Court did helpfully say that where the evidence before a jury was not before the Patent Office, a jury instruction might be appropriate:

Simply put, if the PTO did not have all material facts before it, its considered judgment may lose significant force. Cf. KSR, 550 U. S., at 427. And, concomitantly, the challenger’s burden to persuade the jury of its invalidity defense by clear and convincing evidence may be easier to sustain. In this respect, although we have no occasion to endorse any particular formulation, we note that a jury instruction on the effect of new evidence can, and when requested, most often should be given.

Some of the briefs in this case are available below. You can find additional documents at SCOTUSblog.