Link to full (long) articleThe Barnes & Noble Accusations
The overview, in the slides, of Microsoft's anti-competitive behavior is the following:
Publicly Claiming Control of Android and Other Open Source Operating Systems
Requiring Potential Licensees to Enter into Overly Restrictive Non-Disclosure Agreements
Demanding Royalties Commensurate with Owning the Entire Android Operating Sysem (and Similar to Royalties for a Windows Phone License) Even Though Microsoft Only Owns Trivial Patents
Imposing Licensing Provisions Unrelated to Microsoft's Patents and Designed to Prevent Competitor Innovation
Filing Frivolous Patent Infringement Actions Against Companies That Refuse to Enter Into Anticompetitive Licensing Agreements
Deal with Nokia Includes an Agreement to Engage in a Coordinated Offense Use of Patents Against Open Source Software
Purchasing Patent Portfolios that Threaten Open Source Software
The patents that Microsoft is asserting against Barnes & Noble do not even purport to cover hardware elements or basic software functions for mobile devices, and Microsoft thus has no right to require designers to adhere to any particular hardware or software specifications in order to obtain a license for those patents. Yet Microsoft is doing just that -- abusing and seeking to expand to scope of its patents to control design elements over which Microsoft has no legitimate claim. This conduct is plainly anticompetitive and threatens Barnes & Noble's ability to modify and offer improved products to consumers.... Microsoft only claims ownership of only trivial and non-essential design elements in Android-based devices, as opposed to an entire operating system.
To clarify for people who may not know the background.
For several years Steve Ballmer (CEO of Microsoft) has been making speeches claiming that Linux distributions violate 235 Microsoft patents. They (MS) break this down by program category as to the number of patents allegedly violated. (Android is built on Linux)
The Open Source/Linux Communities have asked repeatedly what patents specifically so they can fix the issues if real. Microsoft has refused to get specific because the patents might be challenged and invalidated.
For the last year or so MS has been making deals with Android device makers to pay patent royalties (what patents and terms are kept under NDA).
Barnes and Noble is the first to actually fight back and at least partially publicize what Microsoft's actual claims and terms are.
Googles recent acquisition of Motorola (not yet finalized) is seen by many as an attempt to build a patent war chest to fight back with. So far Google has been on the outside of these deals and hasn't been able to fight directly as they are not accused direclty by Microsoft and haven't known what patents are claimed to be violated (Google created and develops Android).