Visit Patagonia’s website on just about any day, and you’re greeted by surfers shredding sparkling blue waves, climbers hanging off cliffs, and skiers slashing in front of a melting creamsicle sunset. It’s Branding 101: the type of imagery that makes you want to buy Patagonia. But on Monday, around 4pm EST, the website went black, but for the words: “The President Stole Your Land.”

The new landing page is a shot across the bow at the Trump administration. On Monday, the President announced he was rolling back protections on the Bears Ears and Grand Staircase-Escalante national monuments in Utah; combined, two million acres of land will lose federal protection. It represents the largest reduction of protected land in America’s history, and one that 98 percent of the people who commented on the public review of the monuments are against, according to a study by the Center for Western Priorities. In response, Patagonia has announced its intention to file a lawsuit against the administration to protect Bears Ears national monument from losing federal protection, leaving lands of historical importance to Native American tribes vulnerable to mining, logging, and oil extraction. It’s a case that could define future presidents’ ability to strip monument status like this.

This isn’t the outdoors brand’s first showdown against Trump, having criticized him for leaving the Paris climate change agreement. And the brand has a storied history of environmental activism—Patagonia donates 1 percent of its annual sales, a figure that will approach $10 million in 2017—and consistently launches projects to encourage recycling and reusing clothing. But this is a step further for any company—even Patagonia. “We feel that we have to pull out all the stops at this point,” Hans Cole, Patagonia’s director of environmental activism tells me. “This is not a time to sit back and let any tool available to us go unused.” The brand’s founder Yvon Chouinard was more direct, telling CNN: "I'm going to sue him."

Patagonia and Cole call the administration’s actions “unprecedented” and also illegal. The legal argument Patagonia plans to make against Trump relies on the idea that the Antiquities Act, which gives presidents the power to establish national landmarks, does not mention anything about the ability to later strip that protective status. Woodrow Wilson and Franklin Roosevelt sliced protections in the past, but the legality of those actions was never challenged in court. “It's something that hasn't had to be challenged and we don't think that authority is something [Trump] possesses,” Cole says.

The lawsuit could be a landmark: If Patagonia wins, it sets a precedent that the Antiquities Act is strictly for giving, not clawing back, monument status. Of course, the opposite result could be disastrous for parties like Patagonia that want to preserve these lands. Losing means setting a precedent that presidents have unlimited power to make these protected lands vanish in the future. “If this stands, and we certainly are going to be challenging it in whatever way we can, but if it stands we could see similar attacks on national monuments,” Cole says.

Trump and his supporters argue that federal oversight of these lands takes control away from local leadership. Such a move also frees the land up to be mined and extracted for natural resources like oil—as The New York Times notes, President Clinton prevented the digging of a coal mine when he made Grand Staircase a monument in 1996.

In a column for Fox News, former Utah congressman Jason Chaffetz argues the reductions are long overdue and writes that now “we can even authorize responsible resource extraction.” The potential return of this industry, along with its jobs, to parts of rural Utah is a major talking point, but Cole rejects the idea that the possibility for “responsible resource extraction” exists at these sites.