Microsoft believes that Android infringes several of its patents and maintains an intellectual property licensing program for Android device makers. HTC, a maker of Android mobile devices, is participating in the program and pays an undisclosed royalty to Microsoft.
Amazon is also participating for patents covering its Kindle e-reading device, which competes with the Nook. Were Barnes & Noble allowed to sell its Nook without paying a royalty, it might enjoy a cost advantage over Amazon, which would undermine the incentive to participate in Microsoft's licensing program.
"We have tried for over a year to reach licensing agreements with Barnes & Noble, Foxconn and Inventec," said Horacio Gutierrez, Microsoft's corporate vice president and deputy general counsel of intellectual property and licensing, in a statement. "Their refusals to take licenses leave us no choice but to bring legal action to defend our innovations and fulfill our responsibility to our customers, partners, and shareholders to safeguard the billions of dollars we invest each year to bring great software products and services to market."
Microsoft says that the patents at issue cover tabbing through screens to find information, loading Web pages quickly, and interacting with electronic documents and e-books.
Gutierrez says in a separate blog post that the lawsuit is only Microsoft's seventh proactive patent infringement suit in its 36-year history. "Microsoft is not a company that pursues litigation lightly," he said. "...But we simply cannot ignore infringement of this scope and scale."
Barnes & Noble declined to comment.
Google, however, came to the defense of Android.
"Sweeping software patent claims like Microsoft's threaten innovation," a company spokesperson said in an emailed statement. "While we are not a party to this lawsuit, we stand behind the Android platform and the partners who have helped us to develop it."
Last October, Microsoft filed a patent infringement lawsuit against Motorola for infringing nine Microsoft patents in Android-based phones. In November, the software giant filed a breach of contract lawsuit against Motorola for its refusal to license wireless and video encoding patents. That same month, Motorola sued back, filing three patent actions in Florida and Wisconsin claiming that Windows, Windows Phone 7, Windows Mobile 6.5, Xbox, Bing Maps, Hotmail, Messenger and Exchange Server infringe sixteen separate patents.
Also in October, Gemalto, a digital security firm, sued Google and Android device-makers HTC, Motorola and Samsung, alleging patent infringement. Two months earlier, Oracle sued Google with its own Android-related patent claim.
Last March, Apple sued HTC claiming that the Android handset maker had infringed its patents. And that's just the tip of the mobile patent infringement iceberg.
Update: Added statement from Google.