A Somali family—immigrants who are now legally citizens of the United States—are suing several federal agencies over what appears to have been a particularly rough border detention and search. Their treatment, they say, stems from the government's secretive, unaccountable watchlists.

They family is being represented by the American Civil Liberties Union (ACLU), which has spent years fighting to force a system of due process on the various watchlists that agencies use (and share among each other). Thanks to these lists, hundreds of thousands of people are subjected to increased and intrusive searches when traveling.

The lawsuit attacks two significant and well-established problems with these watchlists. One: Even though these lists supposedly exist to keep an eye on suspected terrorists, they contain hundreds of thousands of names of people with no known ties to terrorist organizations. Two: The system is handled secretly, with almost no oversight or due process. People who end up on the list often cannot find out why or even get the government to acknowledge that they're on a list; their only option is to ask to be taken off the list and hope it happens.

The plaintiffs are the Wilwal-Abdigani family, who in March 2015 traveled from their home near Minneapolis to visit relatives in Canada. According to the lawsuit, they had little trouble passing into Canada but were warned that that the father, Abdisalam Wilwal, had a notation on his records that might result in some additional questions when he attempted to return home.

That proved to be an understatement. According to the lawsuit, when the family tried to return to the United States, border agents confronted them at gunpoint and detained them for hours. The lawsuit says that the border patrol asked Wilwal if the travelers were Muslims and accused him of involvement in terrorism. They handcuffed Wilwal and left him alone in a room for hours without even questioning him. He ended up fainting, and they had to call in paramedics. They eventually questioned him for 45 minutes, though he was detained for more than 10 hours.

The other members of the family were detained separately and were not allowed to leave either. At one point the mother, Sagal Abdegani, realized the agents had neglected to take the cellphone away from one of her children and she managed to call 911 to try to get outside help. An agent snatched the phone away from her. According the lawsuit, border patrol agents also took the couple's 14-year-old son into a separate room and demanded he take off his clothes for a strip search. He refused to comply.

The family was released much later in the day and was allowed to return home. They know now that Wilwal's name is in a federal watchlist database, but they don't know why. They've petitioned the feds to have Wilwal's name removed, but per the federal government's processes, the Department of Homeland Security declined to confirm or deny whether Wilwal is actually watchlisted or whether they removed him from the list. The lawsuit notes, "At no point in the process can an individual appear in person before a neutral decision maker to challenge placement on the watchlist or its consequences."

The family is claiming violations of their Fourth Amendment rights, claiming unconstitutional searches and seizures as well as excessive force. They're also claiming violations of their Fifth Amendment rights to due process, because of the way these federal lists are managed and because of the barriers to clearing Wilwal's name.

For the Fourth Amendment claims, unfortunately, the courts have historically given federal officials very wide latitude to engage in warrantless searches with very little justification at the country's borders. But some important court rulings bolster's Wilwal due process complaint, and the ACLU knows it—because they're involved with some of those suits as well.

These lawsuits involve the federal no-fly list, a subset of these terror watchlists. People on the no-fly list are denied the right to board aircraft under a secretive, opaque system much like the one described in this lawsuit. In 2014 a federal judge ordered the Department of Justice to develop a system where people can determine whether they are actually on the no-fly list and a mechanism for correcting mistaken inclusion on the list. One woman turned out to have been added to the no-fly list by accident (somebody checked the wrong box); she had to fight the government for years to be removed. She only found out about the mistake as a result of the lawsuit.

Read the family's lawsuit here. Read the mother's own account of the border search here.