The long and drawn-out campaign by the Recording Industry Association of America to stop what it calls illegal downloading of music gets a second test beginning Monday when the RIAA retries its case against Jammie Thomas-Rasset.

The trial, which begins Monday in Federal Court in Minnesota, is a remaining vestige of the RIAA's long campaign to stop aspects of online music downloading that it deems illegal. Thomas-Rasset, a 32-year-old mother of four, was convicted in a jury trial in 2007 of illegally downloading and distributing 24 songs via Kazaa.

The verdict was later overturned by the case's presiding judge, who said the penalties leveled against her -- $222,000, or $9,250 per song -- were too high. In recent months, the RIAA has stopped bringing charges against individuals and is seeking to influence Internet service providers to police what it calls illegal music downloading.

Music companies had filed more than 30,000 cases similar to the one against Thomas-Rasset. Her case is exceptional in that it has gone to trial.

Both sides in the retrial expressed confidence they will prevail. Thomas-Rasset's attorney, K.A.D. Camara, has said he believes the case could set an important precedent for other music-sharing cases. Cara Duckworth, an RIAA spokesperson, predicted a court victory for the recording industry.

The suing RIAA companies include EMI Group, Sony Music Entertainment, Warner Music Group, and Vivendi's Universal Music Group.

In the meantime, another legal challenge to RIAA's music-sharing lawsuits is headed to court in New England. Harvard Law professor Charles Nesson, who is defending an accused file-swapper, has argued that the online music downloading of a Boston University student constitutes "fair use" and is therefore legal. Nesson has argued that the RIAA's prosecution of online music sharers is "an unconstitutional delegation by Congress of executive prosecutorial powers to private hands."

Learn about all the latest Enterprise 2.0 technologies at TechWeb's Enterprise 2.0 Conference, Boston, June 22-25. Join us (registration required).