The messages, it turned out, were a hoax. Prosecutors filed criminal charges, saying a lawyer sent the messages to tarnish the professor, his father's rival.

The court case has drawn attention to issues both ancient (the origin of the Dead Sea Scrolls) and decidedly modern (phony online identities).

On Wednesday, a defense attorney asked a judge to throw out most of the charges, saying they put parodies, pranks and freewheeling Internet discussion at risk.

The more than 2,000-year-old Dead Sea Scrolls were found in the 1940s in Israel and include the earliest known version of portions of the Hebrew Bible. They have shed important light on Judaism and the beginnings of Christianity.

Their origin is the subject of an insular, but notoriously heated, academic debate.

Many scholars say the scrolls were assembled by an ancient Jewish group, the Essenes. Others, including University of Chicago professor Norman Golb, say the writings were the work of a range of Jewish sects and communities.

Authorities say Golb's son Raphael was so incensed by the disagreement that he decided to take aim at his father's adversaries, particularly New York University Judaic studies chairman Lawrence Schiffman.

Raphael Golb, a 49-year-old attorney, opened an e-mail account in Schiffman's name and used it to send messages to NYU students and officials in which Schiffman purportedly acknowledged plagiarizing and misrepresenting Norman Golb's scholarship, the Manhattan district attorney's office said. The e-mails asked the recipients to help cover up the supposed misdeeds.

"My career is at stake," some e-mails read.

Prosecutors say Golb also used other aliases to send e-mails and post online articles in an effort to color debate about the scrolls.

Golb faces charges including identity theft and criminal impersonation. He has pleaded not guilty.

Golb contests sending the e-mails. But whoever did send them was just pulling an "intellectual prank" and expressing ideas protected by free speech rights, said Golb's lawyer, Ronald Kuby.

"An attempt to influence a public, academic debate by e-mails and blog postings authored under assumed names cannot be an object of criminal" laws designed to protect people from fraud, threats or physical harm, Kuby wrote in papers filed this week.

Otherwise, prosecutors could target "a vast array of online activities," from parody sites to blog comments made under aliases, he wrote.

The court hasn't ruled on Kuby's bid to get most of the charges dismissed.

Libel isn't an issue in the case: It isn't a crime in New York.

Internet impersonation has generated various civil lawsuits, but prosecutions are much more common in cases that involve stealing money, said Sam Bayard, a fellow at Harvard University's Berkman Center for Internet & Society.

"It's usually very difficult to fit this into a (criminal) legal pigeonhole," he said.

Among Internet impersonation prosecutions was the federal case against Missouri mother Lori Drew. She was accused of helping her daughter and a friend pose as a teen boy on the MySpace social networking site to send hurtful messages to a 13-year-old neighbor girl who committed suicide.

A federal jury in California, where MySpace has its servers, convicted Drew of misdemeanor counts of accessing computers without authorization, but a judge overturned the verdict and acquitted her.

Other online-alias cases have landed in civil courts. St. Louis Cardinals manager Tony La Russa sued the microblogging site Twitter in May over an unauthorized page that used his name, saying it caused him emotional distress by making light of such things as the recent deaths of two Cardinals pitchers. He dropped the case in June.