Few unanimous U.S. Supreme Court decisions are as unilluminating as EBay, Inc. v. Mercexchange. Justice Thomas, writing for the unanimous court holds that patent injunctions are governed by the traditional four factor test that governs injunctions generally, while providing no real interpretive guidance. The District Court erred, he said, by presuming that one class of infringers or patent holders were favored, the U.S. Court of Appeals made the same error in the other direction. Look at it case by case, Thomas urges the lower courts.
But, this unanimous opinion is accompanied by two concurring opinions with very different views on how to apply the Thomas test. Three urge lower courts to defer to a history in which patent injunctions were almost always granted against infringers. Four urge lower courts to recognize that modern patent fights may not look much like those in the past. Justices Alito and Thomas abstain from this debate.
An abuse of discretion standard of review may insulate the high court from having to consider future cases if lower court judges go through hte motions of considering facts on a case by case basis.
If it weren't for the fact the the U.S. Court of Appeals for the Federal Circuit had a monopoly on such cases, this one would be a circuit split in the making on day one.
In the short run, it is a victory for EBay. The Federal Circuit had left it with a certain loss, but now they can make their case again. In the longer run, the decision may help patent infringers only a little, as the strongly pro-patent holder Federal Circuit that originally created a categorical rule in favor of patent holders is likely to favor those Justices who stated in their concurrence that they feel that generally patent holders will end up winning injunctions anyway.