One Wednesday morning in 2018, Ana Suda and friend Mimi Hernández were just chatting in Spanish at a convenience store in Havre, Montana when a border agent interrupted their conversation and questioned their citizenship. Though they said they were born in Texas and California, the agent forced them to show him their driver’s licenses and detained them for about 40 minutes. The May 16, 2018 experience made them feel humiliated and worried that they’d be stopped again in the future for speaking Spanish. Almost a year since that incident, the American Civil Liberties Union filed a lawsuit on their behalf against US Customs and Border Protection.

The women have video from the incident, which does show that the agent questioned their citizenship because they were speaking Spanish. After they showed him their Montana driver’s licenses and detained them, they began to film the encounter. When they asked why he detained them, he said, “Ma’am the reason I asked you for your ID is I came in here and I saw you guys are speaking Spanish, which is very unheard of up here.” The suit, which identifies the agent as Paul A. O’Neal, alleges that the agent also said that Hernández’s accent was “very strong.”

But, as the ACLU points out, judging citizenship on the ability to speak English is dangerous. “Apparently, he believed their use of Spanish justified his actions,” the ACLU’s blog reads. “But just as you can’t be pulled over in your car for no good reason, CBP must have ‘reasonable suspicion’ for a brief investigatory stop and ‘probable cause’ for a longer arrest. The agent who held Ana and Mimi had no legally legitimate reason to do so. In fact, in hearing a similar case, the Ninth Circuit Court of Appeals, the federal court with jurisdiction over Montana, explained that even the inability to speak English cannot by itself justify a border patrol agent’s stop because ‘the same characteristics applies to a sizable portion of individuals lawfully present in this country.’ In Ana and Mimi’s case, the problem is even starker: The agent detained two women who can speak English – merely because they chose to speak a different language with each other.”