FARMINGTON HILLS, MI -- When Michael Coleman, who leads a local Muslim group, was first subjected to extraordinary security measures at Detroit Metro Airport in May 2015, he wasn't enraged or even surprised.

But it was a subsequent trip, this time with his family, that got to him, when his 5-year-old daughter took notice.

"She asked 'Why are they being mean to daddy,'" said Coleman, of Van Buren Township, known in Metro Detroit religious circles as AbdulKarim Yahya.

"She understood that I was being subjected to something unpleasant."

He's one of 18 people who filed a pair of lawsuits Tuesday against officials of the the Terrorist Screening Center, a Virginia-based division of the FBI.

The plaintiffs claim they've been inexplicably added to terrorist watch lists, forcing them to undergo extra screening measures at airports, and at times preventing them from flying at all, or making financial wire transfers.

And one of the plaintiffs is 4 years old.

Referred to as "Baby Doe" in the lawsuit, the child was just seven months old when his parents found that his boarding pass for an airline flight was stamped "SSSS."

That's a sign, according to the Council on American Islamic Relations, which has been fielding complaints on the matter for years, that a person has been placed on a watch list by the Terrorist Screening Center, and can expect to be subjected to enhanced screening, questioning, chemical swabbing and fingerprinting at U.S. airports.

"While passing through airport security, he was subjected to extensive searches, pat downs and chemical testing," alleges the class-action lawsuit filed in Virginia federal court on behalf of a group of people with ties to Metro Detroit.

"Every item in his mother's baby bag was searched, including every one of his diapers...

"At no time was Baby Doe, or his parents, given notice of the factual basis for his placement not he federal watch list, and at no time was he or his parents offered a meaningful opportunity to contest his designation."

The U.S. Homeland Security Department in 2007 established a way to challenge watch list inclusion called the Traveler Redress Inquiry Program, or T.R.I.P., after a government audit showed that the Terrorist Screening Center's database contained inaccurate information.

But activists claim that has not helped.

"There is no meaningful process that the government has instituted in order for someone to challenge their designation on the federal watch list," said Lena Masri, an attorney for CAIR, which helped the plaintiffs file the lawsuit.

"It's a very secretive process... which is merely an inquiry. And the government will conduct a behind-the-scenes... kangaroo review that you never really know what's going on. You never see the evidence that's being used against you. And afterwards, everybody gets a form letter back that says 'We can neither confirm nor deny whether you are on the terror watch list, but if you were added my mistake, rest assured, we fixed that."

One of the lawsuits filed Tuesday calls for a judge to declare the current practices of the Terrorist Screening Center unconstitutional, and to order the government to provide people on the watch list a way to find out why they were listed and contest their inclusion.

The second lawsuit is a class-action complaint seeking damages.

"Baby Doe's only crime was that he was born to an American Muslim family," said Masri.

The government will have 21 days to respond in court.