A recent report by , a market researcher, shows that the percentage of people in the U.S. using a P2P file-sharing service to download music has fallen from 16% in the fourth quarter of 2007 to around 9% after LimeWire ceased file sharing operations last fall.

Even so, Johnson believes that piracy will continue unabated as users turn to other music sharing technologies. NPDs survey, for instance, showed that while LimeWire usage has fallen off the cliff, usage of FrostWire and BitTorrent have shown marked increases.

"The RIAA has put their hands around the necks," of every entity they could, Johnson said. But many of the remaining ones are in the open source realm and are going to be harder to go after.

"There's been a steady stream of closure signs pounded on the walls of Web sites" over the past few years, he said. But every time that has happened users have simply migrated elsewhere, he said. "It's just like a tube of toothpaste. You squeeze one end and it just pops over to the other."

Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at , or subscribe to . His e-mail address is .