The Greyhound Lines bus company announced on Friday that it will stop allowing border enforcement agents to conduct warrantless immigration checks aboard its buses.

The announcement by the nation’s largest bus company came a week after the Associated Press reported that an internal Customs and Border Patrol (CBP) memo stated that private bus companies had to grant agents consent before they could board.

Greyhound had previously said it believed federal law required it to comply with border agents’ requests to board its buses, regardless of whether they had warrants, a practice that began to ramp up in 2018.

In a statement, Greyhound now says that it will tell the Department of Homeland Security, under which CBP falls, that it will no longer assent to warrantless searches of private areas of its company, including buses, terminals, and company offices. The company said it also plans to develop training to ensure drivers and other employees follow the new policy.

“Our primary concern is the safety of our customers and team members, and we are confident these changes will lead to an improved experience for all parties involved,” the Greyhound statement said.

The AP, which first reported on the new policy, said it had not received comment from CBP officials. In a statement to The Hill, a CBP official wrote that searches of buses were “consistent with law and in direct support of immediate border enforcement efforts, and such operations function as a means of preventing smuggling and other criminal organizations from exploitation of existing transportation hubs to travel further into the United States.”

Viral videos began spreading in early 2018 of border patrol agents entering private buses and trains, including Amtrak trains, to ask passengers for proof of citizenship. Such incidents were filmed across the country, in Florida and upstate New York, among other places.

In response, the American Civil Liberties Union (ACLU) and other politicians and organizations called on these companies to enact specific policies against warrantless searches. The ACLU argued that these unwarranted searches aboard Greyhound and other transit companies’ vehicles violate the Fourth Amendment of the US Constitution, which outlaws “unreasonable searches and seizures,” and mandates the use of warrants for law enforcement searches.

“We are pleased to see Greyhound clearly communicate that it does not consent to racial profiling and harassment on its buses,” Andrea Flores, deputy director of policy for the ACLU’s Equality Division, told the AP.

The ACLU has also accused CBP of racially profiling riders during these stops. CBP has said that it asks all passengers aboard for their papers regardless of their appearance.

Greyhound is currently being sued in California court on the grounds that its allowance of border agents aboard amounts to a violation of consumer protection laws.

There’s been ongoing confusion about border enforcement policy

In January 2019, a local comedian in Portland, Oregon, shared his encounter with CBP agents who detained him on a bus from Spokane, Washington. The agents alleged that his papers, documenting his status as an asylum seeker, were falsified.

This interaction — which like many others, went viral — exposed a deep, and ongoing, confusion over how and where border enforcement agencies, including both CBP and Immigration and Customs Enforcement, or ICE, can conduct enforcement work.

By law, documentation checks can take place within 100 miles of any land or water border, a swath of land in which more than half of Americans live. All of Florida is within 100 miles of a border, for example; so is most of New York.

Bus searches at the northern border increased under Trump, according to an investigation by NBC, which found that such checks took place under the Obama administration as well, but required approval from officials at CBP headquarters. That latter requirement was eliminated by the Trump administration.

Under the current rules, individuals cannot be detained during searches unless agents have “reasonable suspicion” that criminal activity, such as smuggling, is taking place. The ACLU has long argued that unwarranted searches aboard Greyhound and other transit companies violate the US Constitution. But Greyhound had argued that those protections don’t apply to private transportation companies.

“We are required by federal law to comply with the requests of federal agents. To suggest we have lawful choice in the matter is tendentious and false,” a spokesperson for Greyhound’s parent company, FirstGroup PLC, said last summer.

But according to the memo reported on by the AP, the former CBP head agreed that warrantless boarding, without consent from the company, violates the Fourth Amendment.

“When transportation checks occur on a bus at non-checkpoint locations, the agent must demonstrate that he or she gained access to the bus with the consent of the company’s owner or one of the company’s employees,” the memo, signed by then-chief Carla Provost.

Provost retired from the agency at the end of January.

Still, even with clearer guidance about what private transit companies must comply with, the law about where and when law enforcement can conduct sweeps remains murky in some places. For example, racial profiling is not completely illegal during searches: as Vox’s Alexia Fernández Campbell has written, race can be part of the equation when determining reasonable suspicion:

In United States v. Brignoni-Ponce, a 1975 Supreme Court case, the Court ruled that it was a violation of the Fourth Amendment for Border Patrol agents to stop a car only because the driver looked Mexican. But while the Court agreed that “apparent Mexican ancestry” does not, on its own, justify reasonable suspicion that a person is undocumented, the justices did rule that it is a “relevant factor.” To justify a stop, the Court said an agent needs several reasons to pull over a car near the border, such as observing a heavily loaded van or a car with an unusual number of passengers. That could also include “the characteristic appearance of persons who live in Mexico, relying on such factors as the mode of dress and haircut.” In other words, race can be part of the equation.

And this sort of ambiguity remains an issue of import, particularly given the new policy does not mean searches will end, only warrantless ones.