Microsoft chief executive Steve Ballmer says Red Hat Linux users are violating the firm's intellectual property and will have to compensate Microsoft as a result.
At a London Microsoft event last week, Ballmer told the audience, "Red Hat users will have to eventually compensate us."
Ballmer had praised Linux distributor Novell for making a deal with Microsoft over intellectual property, which meant its users would not be subject to any intellectual property violation claims by Microsoft, but singled out Red Hat users for being open to any claim.
In the past, Ballmer has said the Linux operating system violates certain Microsoft patents, but he has not been specific on which areas, and at the London event the audience weren't any wiser either.
Ballmer said that when Microsoft had been found on the wrong side of patent law, the firm had written out big cheques as a result, and the Linux community should be subject to the same rules.
He did not say when Microsoft was going to move against the Red Hat Linux community and its end-users.