The Supreme Court yesterday rejected Microsoft's appeal against a $290 million patent suit brought by i4i.
The case dates back to 2007, when i4i claimed that Microsoft Word infringed its XML editor patent. Two years ago, a Texas District Court ordered Microsoft to pay $290 million and remove Word from the market.
Later appeals failed, and Microsoft removed the offending XML editor from all copies of Word but filed another appeal.
Microsoft yesterday had one last shot at defending itself, arguing that the patent should never have been issued. The standard of proof is set too high, it claimed. But the court disagreed.
"This Court is in no position to judge the comparative force of the parties' policy arguments as to the wisdom of the clear-and-convincing-evidence standard that Congress adopted. Congress specified the applicable standard of proof in 1952 when it codified the common-law presumption of patent validity," it said in its decision.
"During the nearly 30 years that the Federal Circuit has interpreted §282 as the Court does today, Congress has often amended §282 and other patent laws, but apparently has never considered any proposal to lower the standard of proof."
The decision will be a blow, not just for Microsoft but for the many other technology companies facing battles with so-called patent trolls.
Indeed, dozens and dozens of other companies, including Apple and Google filed Amicus briefs in support of Microsoft's case.
If Microsoft wants to take things further, it will have to apply to Congress and push for a change in regulation.