Power Integrations makes energy-efficient analog chips for power conversion. The company has scared off five infringers to date, including recent filings against Fairchild Semiconductor and System General. The company hopes the cases they have won will act as a deterrent, but are not sanguine in that prospect. Investor relations mouthpiece Joe Shiffler: "Clearly the demand for more energy-efficient electronic products has been increasing. That has created some motivation for people to co-opt our technology."

Companies chasing a clean regime have paid attention to protecting their turf, foreseeing that this is merely the beginning of a scramble for what will become a very crowded sector. With so many chasing the same game, putting a proprietary stamp on a patch of innovation is one of the best hedges for staying in the game. The cost is enforcing the patch against the inevitable interlopers.