SunnComm Technologies, a developer of CD antipiracy technology, said Thursday that it will likely sue a Princeton student who early this week showed how to evade the company's copy protection by pushing a computer's Shift key.

Princeton Ph.D. student John "Alex" Halderman published a paper on his Web site on Monday that gave detailed instructions on how to disarm the SunnComm technology, which aims to block unauthorized CD copying and MP3 ripping. The technology is included on an album by Anthony Hamilton that was recently distributed by BMG Music.

On Thursday, SunnComm CEO Peter Jacobs said the company plans legal action and is considering both criminal and civil suits. He said it may charge the student with maligning the company's reputation and, possibly, with violating copyright law that bans the distribution of tools for breaking through digital piracy safeguards.

"We feel we were the victim of an unannounced agenda and that the company has been wronged," Jacobs said. "I think the agenda is: 'Digital property should belong to everyone on the Internet.' I'm not sure that works in the marketplace."

The cases are already being examined by some intellectual-property lawyers for their potential to test the extremes of a controversial copyright law that block the distribution of information or software that breaks or "circumvents" copy-protection technologies.

Several civil and criminal cases based on the Digital Millennium Copyright Act have been filed against people who distributed information or software aimed at breaking through antipiracy locks. In one, Web publisher Eric Corley was banned by a federal judge from publishing software code that helped in the process of copying DVDs.

In a criminal case, Russian company ElcomSoft was cleared of charges that it had distributed software that willfully broke through Adobe Systems' e-book copy protection.

Both of those cases dealt with software or software code, however. The issue in Halderman's case is somewhat different.

In his paper, published on the Princeton Web site on Monday, the student explained that the SunnComm technique relies on installing antipiracy software directly from the protected CD itself. However, this can be prevented by stopping Microsoft Windows' "auto-run" feature. That can be done simply by pushing the Shift key as the CD loads.

If the CD does load and installs the software, Halderman identified the driver file that can be disabled using standard Windows tools. Free-speech activists said the nature of Halderman's instructions--which appeared in an academic paper, used only functions built into every Windows computer, and were not distributed for profit--meant they would not fall under DMCA scrutiny.