In July last year, Rockstar Bidco, a consortium of Apple, BlackBerry maker Research In Motion (RIM), Microsoft, Ericsson, Sony and EMC bought 6,000 patents of defunct Nortel for a whopping $4.5 billion, after an intense bidding war that saw Google end up on the losing side. Google cried foul after its defeat saying its success in the mobile market had resulted in "hostile, organised campaign against Android by Microsoft, Oracle, Apple and other companies, waged through bogus patents."
Back in present day, according to a report by Korean news agency Yonhap News, Apple has been busy acquiring some of Nortel's patents from the consortium it reportedly owns a 58% stake in. According to the report, Apple has so far acquired 1,024 of these patents, with 695 already transferred to Apple, while the rest are in the process of being registered.
So why buy patents from a consortium you're already a stakeholder in? According to Business Insider's Owen Thomas "Getting full rights to the patent likely helps Apple use the patents offensively in its ongoing lawsuits. If you do not own a patent, but merely have licensed it, you can't go out and sue someone for using the patent. Having outright ownership of a patent allows Apple to use the patents offensively."
Interestingly, Rockstar's general counsel Mike Dunleavy denied reports that Apple or any other company has a "controlling" stake in Rockstar Bidco. Apple and Microsoft offered no comments to the Yonhap News report.