"Congress has already gone a long way to fix patent abuses," Johnson said.
Additional changes in patent law could hurt small businesses that hold patents, added Graham Gerst, a partner in the Global IP Law Group. Many small companies that own patents are reluctant now to sue infringers because of the high costs of litigation, he said.
Any legislation that would further discourage patent lawsuits would deteriorate the value of those patents, he said.
The SHIELD Act would discourage NPEs from buying patents, thus hurting inventors who want to sell their patent portfolios, he added.
Several court decisions in recent years and the 2011 patent reform legislation have made it harder for PAEs to extract settlements, said Representative Melvin Watt, a North Carolina Democrat. "Much has been done that acknowledges and tackles certain behaviors that must be discouraged," he said.
It's difficult to define just who is a patent troll, Watt added. Late last year, a group of buyers, organized by large patent holding company Intellectual Ventures, accused by critics of being a patent troll, bought 1,100 patents from Kodak and saved it from bankruptcy, Watt noted.
"The purchase undoubtedly saved thousands of jobs," Watt said. "It also enables a nonpracticing entity to pursue litigation against other infringers on patents duly acquired from Kodak."
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