Barely 24 hours after President Donald Trump signed an executive order barring nearly all refugees, and immigrants from seven majority-Muslim countries, from entering the United States, the federal government has to defend the order in court.

During a 7:30 pm emergency hearing Saturday in a Brooklyn courthouse, a federal court will consider whether to temporarily halt the deportation of two Iraqi visa-holders detained at JFK International Airport Friday night — and dozens or even hundreds of others who have been detained in airports around the country as a result of the ban.

The two men on whose behalf the suit was originally filed, Hameed Khalid Darweesh and Haider Sameer Abdulkhaleq Alshawi, had worked with the US military in Iraq and had their lives and families threatened as a result. Darweesh was released from Customs and Border Protection custody Saturday afternoon; Alshawi, according to CNN, “will reportedly be released” Saturday evening.

But just getting released from detention doesn’t necessarily clear them from the ban; lawyers haven’t been immediately clear on the formal status the men have in the US right now. And the lawsuit goes beyond the two named defendants. The groups challenging the ban — including the ACLU, the National Immigration Law Center, the International Refugee Assistance Project, and a Yale Law School clinic — want the court to issue the same protections to other immigrants and refugees detained in airports across the US.

It’s not publicly known how many immigrants are detained at airports as a result of the ban, or even who they are. The court complaint in the New York case says that “dozens and dozens other individuals currently detained at JFK”; unverified reports indicate that 50 detainees may be held in the Dallas airport, while other unconfirmed reports indicate immigrants are being held in Atlanta, Houston, Detroit, and Dulles (outside Washington, DC).

The initial lawsuit, filed Saturday morning, asks the court to agree to treat all immigrants being detained under the ban as a class — and to issue an injunction preventing Customs and Border Protection agents from detaining anyone solely on the basis of Trump’s executive order. The injunction wouldn’t strike down the order itself, but it would force CBP agents to stop one aspect of its implementation until the court, and America, has figured out what’s going on.