Portland protesters allege that federal law enforcement officials are driving through the streets of Portland, Oregon in unmarked cars and interrogating them as part of an effort to quell their First Amendment rights.

According to Oregon Public Broadcasting, a protester named Mark Pettibone and his friend Conner O’Shea were demonstrating outside the Multnomah County Justice Center in Downtown Portland when a group of men in camouflage jumped out of an unmarked van and chased after them. While O’Shea managed to hide, Pettibone was taken by the men to the federal courthouse and put inside a cell. He was interrogated for 90 minutes before he was released.

“I just happened to be wearing black on a sidewalk in downtown Portland at the time,” Pettibone told OPB. “And that apparently is grounds for detaining me.” (While the U.S. Marshal Service told OPB it wouldn’t comment on whether it used unmarked vehicles to ambush and arrest peaceful protesters, it did confirm that the agency “did not arrest or detain Mark James Pettibone.”)

For the past month and a half, activists in Portland have appeared outside the courthouse to protest against police brutality and institutional racism in response to the brutal killing of George Floyd. Portland has long been a site of activism and peaceful protests, a reputation that contrasts sharply with the local police force’s excessive use of force, as Rolling Stone previously reported.

President Trump has repeatedly criticized city and state officials for what he perceives to be their impotent response to the protests, and has vowed to take action by sending federal officials. In response, Portland public officials have blasted Trump and acting secretary of Homeland Security Chad Wolf for their use of excessive force, pointing to the use of tear gas and rubber bullets against journalists and protesters.

Wolf arrived in Portland earlier this week to meet with federal officials and has issued a lengthy statement referring to protesters as a “violent mob” of “anarchists.” Trump recently ordered the federal law enforcement to intervene in the protests, referring to them as “out of control” and saying “the locals couldn’t handle it.” Both Gov. Kate Brown and Mayor Ted Wheeler have requested that the feds to leave the city.

“A peaceful protester in Portland was shot in the head by one of Donald Trump’s secret police,” Sen. Ron Wyden (D) tweeted, referring to the shooting of peaceful protester Donovan Labella, 26, on the streets of Portland on Saturday night. (La Bella was severely injured and hospitalized.) “Now Trump and Chad Wolf are weaponizing the DHS as their own occupying army to provoke violence on the streets of my hometown because they think it plays well with right-wing media.”

In a statement shared with Rolling Stone, Jann Carson, interim executive director of the ACLU of Oregon, said the federal government’s practices in Portland established a bone-chilling precedent for peaceful protests nationwide. “What is happening now in Portland should concern everyone in the United States,” he said. “Usually when we see people in unmarked cars forcibly grab someone off the street we call it kidnapping. The actions of the militarized federal officers are flat-out unconstitutional and will not go unanswered.”