The New York Civil Liberties Union, in what it says is an effort to expose possible government spying on law-abiding activists, is starting a campaign to teach “radical” activist groups how to obtain their own government surveillance files from the FBI, Pentagon, and New York City Police Department through the use of federal Freedom of Information Act and local Freedom of Information law requests.

Some critics are saying the program could interfere with law enforcement activity and may even inadvertently help extremists who use legitimate protest groups as cover for terrorist activities.

The campaign, called “Spy Files,” was described in an e-mail message from an NYCLU field organizer, Ari Rosmarin. The electronic message, obtained by The New York Sun, invited activist groups at several area universities to a training session being held at the NYCLU offices tomorrow evening. The email urges recipients to forward the invitation to “as many radical/environmental/peace/arab-muslim-southasian/dissent groups as you can think of.” Although the message specifically refers to peace groups, it does not specify that only peaceful groups are welcome.

“We feel that organizations have a right to know,” the field director and legislative counsel at the NYCLU, Udi Ofer, said. “Political dissent is one of the most fundamental rights of anyone living in the United States. … We’re very concerned that government is using its precious resources to spy on people based on their First Amendment activities.”

Mr. Ofer cites specific incidents in the past few years in which the American Civil Liberties Union was able to obtain documents or videotapes confirming that the government had monitored activist groups, including the Rhode Island Community Coalition for Peace; the Quaker group American Friends Service Committee, and the Broward Anti-war Coalition of Florida.

About a dozen organizations will be in attendance at tomorrow’s training, ranging from civil rights to anti-war groups, Mr. Ofer said, but he declined to disclose their names due to what he said were privacy concerns.

Upon learning of the NYCLU program, a homeland security fellow at the Manhattan Institute, Michael Barrett, said “Spy Files” itself could be unintentionally giving aid to extremists by thwarting law enforcement’s ability to secretly monitor groups of interest.

“Anything that has the potential to impede legitimate law enforcement activities has the potential to help terrorists,” he said. “It’s naïve to say, ‘It’s a nonprofit, or it’s an activist group, so there’s no danger.’ … Even if the organization is not involved” in terrorist activities, “a small swath of people in that organization may be involved.”

And “if you haven’t done anything wrong,” Mr. Barrett said, “that actually helps to free you up from suspicion.”

However, a student activist at New York University who fears that the government is monitoring his activities, Jordan Dunn, told the Sun in an e-mail message, “While it’s true that I don’t have anything to hide, I still find this” government surveillance “objectionable.”

Mr. Dunn, who is president of NYU’s Middle East Dialogue Group, “which works to promote peaceful co-existence between Arabs and Jews and to maintain friendly campus relations,” said, “I’m sure that simply by e-mailing the leaders of Arab groups on campus, I’ve subjected myself to warrantless snooping.”

Mr. Dunn said his fears were justified when in April a freedom of information request showed that the Defense Department had monitored an NYU law school gay and lesbian group called OUTLaw, as well as other groups at universities in California, for their planned protests of campus military recruitment.

“It’s clear that the Department of Defense is abusing powers it’s gained since 9/11 by monitoring groups like OUTLaw who pose no terrorist threat whatsoever. … The Department of Defense is simply monitoring any kind of dissent. Not only is this dangerous to our freedom of speech, this is a waste of millions of tax dollars that could be put to much better use in the war on terror,” Mr. Dunn said.