Under the terms of the Combined Federal Campaign, which ladles out some $250 million a year from contributions made by members of the armed forces and federal government employees, organizations participating in the program must sign an agreement that they will not knowingly employ individuals whose names appear on several federal watch lists.

According to the New York Times, the ACLU had originally signed the agreement in the belief that it prohibited only knowingly employing anyone whose names appear on the watch lists. But an article in Saturday's Times reported that those participating in the program must monitor their employment lists to be sure they have no employees on the watch lists.

The group had signed the charity drive's certification in January. Anthony D Romero, the ACLU's executive director, told the Times he had not inspected the watch lists or compared them to the ACLU's employment records. He added that his lawyers had advised him that he could sign the certification in good faith because it prohibited only knowingly employing those listed.

"The ACLU would not have signed the CFC funding agreement if we thought we had to check our employment records against a government blacklist," Mr. Romero said in an interview yesterday, revealing that the group had pulled out of the program.

But Mara T. Patermaster, the CFC's director, told the Times last week that the program required diligent efforts from participants. "We expect the charities will take affirmative action to make sure they are not supporting terrorist activities," Patermaster said.

On Saturday, Romero told the Times that thousands of charities presumably have signed the certification, and the ACLU posted a list of charities that participated in the drive in 2002 on its Web site. The CFC list includes scores of familiar names, including the ASPCA, National Public Radio and the NAACP Legal Defense and Educational Fund.

Romero wrote to Patermaster yesterday, saying he was "disturbed and surprised" that the charity drive required nonprofit charities to check their employees against a "blacklist" in order to receive donations. He wrote that "the lists are notoriously riddled with error and do not provide individuals with a means to correct false information."

"It's increasingly clear," Romero said, "that the Patriot Act and the government's war on terror threatens America's charities as well."

The idea that possibly harboring someone on a list of potential terrorists could also threaten America's security does not appear to have bothered the ACLU.

Editor's note: