A federal judge will hear arguments on whether a government watchlist of more than 1 million "known or suspected terrorists" violates the Constitution.
The Council on American-Islamic Relations sued in 2016 on behalf of Muslim Americans who say they were wrongly placed on the list and suffered negative consequences as a result.
The government's no-fly and selectee lists, which bar some people from flying and force others to go through extra screening, are derived from the watchlist.
The plaintiffs say the list is disseminated so broadly that those listed face not only travel woes but also difficulty completing financial transactions and interacting with police.
The plaintiffs also say the standard for inclusion is overbroad and innocent Muslims are routinely listed by mistake.
A hearing is scheduled Thursday in Alexandria.