"Without a Social Security number you are anonymous," said Gadiel, who also serves on FAIR's advisory board. "You could be John Doe or [Sept. 11 hijacker] Mohammed Atta."

Gail Moran, the MVA's legislative and regulatory manager, said Gadiel's argument is misleading.

She notes if the bill becomes law, applicants without Social Security numbers would have to show other forms of identification and citizenship -- such as birth certificates, work visas or passports.

"I don't think the ads address what is contained in the bill as passed by the General Assembly," Moran said.

Del. Joseph F. Vallario Jr., chairman of the House Judiciary Committee who worked to amend the bill, called the radio ads "grossly misleading."

Latino and social activists say the radio spot airing in Maryland is the latest example of the tactics that FAIR has employed for years to discourage U.S. immigration and political candidates who do not embrace its agenda.

In 2000, FAIR spent $1 million on a media campaign -- which was widely condemned as being unfair -- to defeat former Michigan Sen. Spencer Abraham. Abraham, who is now U.S. energy secretary, had helped write a bill in Congress that let more than 200,000 skilled foreign workers enter the United States.

More recently, FAIR -- which was founded in 1979 -- has been criticized for attempting to use the Sept. 11 terrorist attacks to push its anti-immigration agenda.

"FAIR is not shy about exploiting fear of the stranger, be that stranger a refugee from Haiti or a would-be terrorist from the Middle East," said Rick Swartz, a Washington attorney who founded the National Immigration Forum, a group that embraces immigration to the United States. "They have been quite effective at taking a kernel of truth and blowing it up into a fountain of suspicion."

Dan Stein, executive director of FAIR, defended his organization's tactics.

"We have been focusing on document fraud for 25 years, and 9/11 was just a vindication of the concerns we have been raising all along," said Stein, who lives in Rockville.

He also stands by the radio ad, saying, "Some folks have a problem with the First Amendment."

But Propeack is calling on Maryland residents and the Ehrlich administration to reject FAIR's strategy.

"They are opportunists," Propeack said. "What they are really trying to do is get this message out that immigrants are terrorists, immigrants caused 9/11."