They're all suing each other. I'm sure someone will post that chart that shows all the mobile players and their largely reciprocal lawsuits amongst each other.
This is standard procedure among the big companies and it's how the business works. They do this to try and get corps to pay licensing fees to each other, and the lawyers encourage it because lawyers like money. I doubt many of these are really adversarial, it's just big business in its normal course trying to get as much money out of everyone as possible, and establish a precedent that if you don't comply with demands, it will cost you even more money. This, of course, is not really relevant to these big companies anyway unless one of these cases establishes a harmful or undesirable precedent.
This is standard procedure among the big companies and it's how the business works. They do this to try and get corps to pay licensing fees to each other, and the lawyers encourage it because lawyers like money. I doubt many of these are really adversarial, it's just big business in its normal course trying to get as much money out of everyone as possible, and establish a precedent that if you don't comply with demands, it will cost you even more money. This, of course, is not really relevant to these big companies anyway unless one of these cases establishes a harmful or undesirable precedent.