U.S. Immigration and Customs Enforcement violated Jeanette Vizguerra’s First Amendment rights by detaining — and planning to deport — the Colorado immigration advocate, her attorneys argued in federal court in Denver on Friday.

ICE says Vizguerra entered the U.S. from Mexico illegally in 1997 and is being held pending deportation. In a statement shortly after her arrest, ICE said the mother of four has a final deportation order and “has received legal due process in U.S. immigration court.”

Protesters gathered outside the Immigration and Customs Enforcement facility in Aurora early Tuesday morning on reports that immigration activist Jeanette Vizguerra was taken into custody.