Most software and Internet firms have pledged not to sue unless someone first sues them. Sun, Google, Oracle, Cisco and many more think that patents would have an ugly effect on the market otherwise. Apple appears to have left that defensive ideal by waging patent war with Android using HTC as its proxy.
By threatening companies that deliver with Android software - they probably hope scare them off. Perhaps like when Microsoft sued Tom Tom or used SCO to ram Linux. Apple uses 20 patents that are terribly week to any person skilled in software, but as with many patents take their toll on common sense in litigation.
Engadget has the full list of Apple patents in this suit and they represent the sorry standard for what is patentable today. This has little to do with innovation, but rather by pushing overly broad claims on what is possible trough a patenting office unfit to manage or deal with abstract matters such as software.
This is yet another reason, after EOLAs return, why we need to scrap software patents to save innovation.
Shame on Apple.