Microsoft has suggested in recent years that companies using the Linux computer-operating system might be violating Microsoft patents. But one group is hoping to fight back by using Microsoft’s own former patents. The Open Invention Network (OIN), a group made up of Microsoft competitors and Linux advocates,said it’s close an agreement to buy 22 patents that Microsoft sold to another organization earlier this year. According to WSJ, the patents may relate to Linux. Microsoft has said that it holds more than 50,000 patents, according to the Journal, and that it believes 200 of those’re violated by Linux applications. The OIN believes that getting these patents’s critical to protecting Linux developers from costly lawsuits, according to the Journal, reports.