That, and in the current business climate, and the way the US patent system works, they pretty much have to do this - it's just good business strategy. If they

That, and in the current business climate, and the way the US patent system works, they pretty much have to do this - it's just good business strategy. If they don't patent it, someone else will, and will go after apple for buckets of cash. In general, it's just a patent cold-war style arms race between large companies - they all keep huge patent portfolios so they all don't bother suing each other for patent infringement, because they're pretty much guaranteed to be infringing on a bunch of each other's patents - it creates a legal situation that neither party wants to get involved with in the first place.