In its single-minded drive to gain advantage, maintain market share and prevent competitors from emerging, like most corporate action, the behaviour of Microsoft rarely surprises me. Microsoft is waving the threat of patent violation at open source software, GPL and Linux in particular, in order to drive customers away from open source Linux. I emphasize patent violation here because a mere two weeks ago, The US Supreme Court ruled in favour of Microsoft in a lawsuit AT&T brought against the Redmond behemoth for its own infringement of AT&T patents on voice recognition software. Microsoft knowingly engaged in this patent violation, has not denied it, but argued that because the software was being sold in China through various agents, any patent violation was not under US jurisdiction.
Despite its record of resistance toward open source document formats being adopted by various state governments, Microsoft thinks that it has been an industry friend to open source and that the newest Gnu Public License will "tear down the bridge between proprietary and open-source technology that Microsoft has worked to build with the industry and customers." It probably comes as quite a surprise to most people to learn that Microsoft has been building a bridge between "proprietary," i.e. Microsoft, and open source technology but this is what they say. This is nonsense, of course, and recognized as such by a growing body of organisations such as the Indian state of Tamil Nadu, which announced that it would move to open source software, citing concerns over "security and the high cost of Windows systems."
Nonetheless and in spite of their propaganda, Microsoft appears to have little or no compunction about violating patent rights and fighting for the right to do so all the way to the Supreme Court, while berating others for violating Microsoft patents, which are based mostly on software Microsoft has either stolen or co-opted.