Mark Lemley asserted a couple of times that actual copying of patented technology is only alleged in a tiny fraction of software patent suits. In other words, most litigation stems from inadvertent infringement. Michael Meurer added that there is a direct correlation between the amount of money a company spends on research and development and the likelihood that it will be sued for patent infringement. In most fields, he notes, piracy (his word) of patents is used as a substitute for research and development, so one would ordinarily see most suits leveled against companies which don't do their own R&D. In software, the companies which are innovating are the ones being sued.