https://www.techdirt.com/articles/20181014/23093340839/decade-after-trying-to-block-open-source-patent-pool-buying-patents-microsoft-joins-pool-entirely.shtml

Almost exactly a decade ago, for reasons I still don't quite understand, Microsoft invited me to sit down one-on-one with their then Deputy General Counsel for intellectual property, Horacio Gutierrez (who is now General Counsel at Spotify). It was, to say the least, a bizarre conversation in which he repeatedly tried to justify Microsoft's position on software patents, with us getting into a spirited debate over Microsoft's ridiculous FUD campaign about Linux. Suffice it to say, while the conversation was fun, we agreed on almost nothing. For a few years, Microsoft had been trotting out claims that Linux violated over 200 of its patents, and kept making these vague threats about it. It never named the patents in question. It never sued. It just kept obliquely warning that those who used Linux might somehow eventually face some patent infringement suits from Microsoft. Some might call this a patent chilling effect. Or FUD. Or a shakedown. No matter what you call it, I stand by the claim that it was despicable.

Partly in response to all this nonsense saber rattling by Microsoft, in 2005 a group of companies who relied heavily on Linux got together to create the Open Invention Network (OIN), which was designed as a giant patent pool, mainly to protect Linux. Basically, all the companies who join agree to license their patents freely for use in Linux (and Linux offshoots) to other members of the network. A large part of the reason for this was to allow various companies working on Linux to freely share patents among each other and protect them from Microsoft-style shakedowns. In 2009, OIN ended up buying a bunch of Microsoft patents for itself to help with its mission -- but here's part of what was amazing about that: Microsoft tried to block the sale, refusing to let OIN be a part of the bidding on those patents. Instead, OIN had to use a third party as a shell bidder so that Microsoft didn't know that OIN was trying to get those patents.