The US Patent and Trademark Office has nullified a troll's app-rotation patent that is the subject of several infringement lawsuits brought against some of the biggest names in the tech sector.

Cloud-computing company Rackspace, a target of a lawsuit from Rotatable Technologies, refused to pay $75,000 to settle a suit and challenged the company's patent, US PAT. No. 6,326,978. Rackspace won, and the patent was declared unpatentable.

"This means that Rackspace will not pay one penny to this troll, nor will Apple, Netflix, Electronic Arts, Target, Whole Foods, or any of the other companies sued by Rotatable for how they use screen rotation technology in their apps," Van Lindberg, a Rackspace vice president, wrote on the company's blog in a post headlined: "Another Patent Troll Slain. You Are Now Free To Rotate Your Smartphone."

Rotatable's patent was on the functionality that rotates a screen on a smartphone to go into landscape mode. That claim enabled it to sue just about any app developer out there, just for calling up a simple functionality used by many apps. Rackspace was being sued over its Rackspace Cloud Notes app for iOS in a lawsuit that also contained claims again several other Texas companies, including Petroleum Geo-Services, PlainsCapital Bank, Texas Instruments, Schlumberger Technologies, and energy giant TXU. All of those companies have iOS apps which, apparently, rotate their screens.

Rotatable sued [PDF] in February. The patent was nullified as part of a so-called inter partes review before parent regulators. Such reviews have been available for several years, but it's now somewhat easier to invalidate patents with that process because of changes made in the America Invents Act.

"Rotatable sued us and immediately asked for $75,000 to go away. We refused. And we fought. It's Rackspace policy to not pay off patent trolls, even if it costs us more to fight," Lindberg wrote. "Eventually Rotatable offered to just walk away—but we refused again. Just as we promised last year, we challenged the patent and the USPTO invalidated it."