In late January, the city turned over about 600 pages of intelligence digests to the civil liberties union and other lawyers suing the city on behalf of people who say they were wrongly arrested and detained during the convention. The documents are under court seal, but Mr. Dunn and a lawyer for The Times have asked a federal court magistrate to make them public.

City lawyers have described the intelligence documents as central to the city’s defense.

“They detail what information the N.Y.P.D. relied on in formulating its policies,” Gerald C. Smith, an assistant corporation counsel with the Law Department, wrote in a letter filed in federal court last month. He said the intelligence helped the police forecast how many people were coming to New York for the convention and had spoken about breaking the law.

Moreover, Mr. Smith wrote, the intelligence showed the city was justified in applying intensive scrutiny to the 1,806 people arrested during the convention, including fingerprinting more than a thousand people who faced charges no more serious than traffic tickets. Some were detained as long as two days for minor offenses.

“The decisions to adopt those policies were based in large part upon intelligence that had been gathered regarding the number of individuals planning to attend the R.N.C. in some capacity and the number of groups and individuals intending to, or at least professing to intend to, engage in unlawful behavior,” Mr. Smith wrote.

In ruling that some of that information could be used by the city for its defense, a federal magistrate judge said that a debate over security and First Amendment rights would come to a head in the litigation.

“The questions posed by these cases have great public significance,” the judge, James C. Francis IV of Federal District Court in Manhattan, wrote on March 12. “At issue is the proper relationship between the free speech rights of protesters and the means used by law enforcement officials to maintain public order.”

One group that learned it had been the subject of an intelligence report, Billionaires for Bush, offered a lighthearted response to the news. The group, a satirical troupe, dresses in tuxedos and gowns to provide faux endorsements of the administration.

Marco Ceglie, a national co-chairman who performs as Monet Oliver DePlace, said a member of the group known as Meg A. Buck had issued a statement: “We suspect they were looking for stock tips.”