Blackberry are in no place to do this, Ericsson haven't been of this nature, and whilst Sony could they have enough distraction going on at the moment to focus their attention elsewhere. I also feel those three would gleefully follow Apple and Microsoft.
It looks and feels, from the viewpoint of a lay observer, to be an Apple and Microsoft effort.
Time will tell though, it may take a while but everything comes out in court, the good stuff and the bad.
http://arstechnica.com/tech-policy/2012/12/jury-finds-iphone...
The CEO of the firm they set up to do the trolling is also the CEO of MPEG-LA that collects patent fees for H.264 and a few other royalty bearing standards.
It's not unreasonable to suspect that this action was planned as part of that formation and priced into the bid.
Now that the worm has turned and Apple has their do-over we can see that they never changed their spots. They just improved their legal tactics.