Jessica Litman, a professor at Wayne State University who specializes in copyright law, says the bill echoes a landmark 1984 Supreme Court case, Sony v. University City Studios, that permitted the sale of VCRs. "It seems to restore the Sony test that if you're making legitimate technology that also has a circumvention application, it's only illegitimate to distribute it if the legitimate application is not significant," Litman said.

Litman, who is a critic of the DMCA, says its anti-circumvention sections have not actually been used to thwart online piracy. "So far it's been used chiefly in cases where no copyright infringement has been alleged or proved," she said. "So far it doesn't seem to have been a very important bulwark against infringing behavior in the first place."