A jury in North Dakota has found Greenpeace liable for defamation, trespassing and a suite of other infractions in a case that pitted the environmental advocacy group against Energy Transfer, the company that built the Dakota Access oil pipeline.

On Wednesday, the jury awarded the pipeline company hundreds of millions of dollars in damages. Greenpeace says the total judgment, approximately $660 million, could significantly damage the organization and represents an attack on free speech within the country.

“I think Energy Transfer, and this is probably true of many big oil companies, is trying to send a message to other organizations that if you try and hold power to account, we will try to silence you. We will try to bankrupt you,” says Sushma Raman, interim executive director of Greenpeace USA. Raman said Greenpeace will appeal the decision.

The case focused on Greenpeace’s participation in protests at the Dakota Access pipeline in North Dakota during its construction nearly a decade ago. It raised key issues around the limits of free speech and whether private companies can claim restitution from protesters who block or delay a project.

The jury decision “should be cause of concern to people who participate in peaceful protest, who organize advocacy efforts, who show up in solidarity,” says Raman.

But the company, Energy Transfer, praised the verdict. The company’s counsel for the trial, Trey Cox, wrote in a statement that “Peaceful protest is an inherent American right; however, violent and destructive protest is unlawful and unacceptable.” The decision, he writes, represents “reckoning and accountability for Greenpeace.”

In 2016, the pipeline began to face opposition from the Standing Rock Sioux Tribe, whose reservation sits near the route. They argued the pipeline posed a threat to their water supply where it passed near their reservation — a claim Energy Transfer has denied.

Thousands of demonstrators, including many from Greenpeace, joined the tribe in their protests, citing concerns with tribal sovereignty alongside environmental and climate concerns. Demonstrators camped out for months to try to block the project, drawing worldwide media attention.

Greenpeace had a significant presence at the protests and used its global reach to draw attention to the opposition. In the lawsuit, Energy Transfer says Greenpeace participated in a publicity campaign that hurt the project and the firm’s bottom line — allegedly raising the cost of construction by at least $300 million.

Greenpeace denies the allegations, saying it played a limited, supporting role in the protests, which were led by Native American groups. The organization said the lawsuit was an attempt to quell their First Amendment rights and have a chilling effect on future protests, especially those related to climate change and environmental activism.

Jennifer Safstrom, a First Amendment legal expert at Vanderbilt University, says the lawsuit had a chilling effect on protest even before the verdict. “This jury verdict is obviously a huge and monumental milestone in the case because of what the implications are, not just for Greenpeace, but for other advocates,” she says. “Advocacy defendants will now potentially face huge liability in possibly similar litigation,” even in fields outside the realm of environmental advocacy.

Oil executive says, “They’re going to pay”

The Dakota Access Pipeline moves crude oil 1,172 miles from the booming oil fields of North Dakota to a pipeline hub in Patoka, Illinois. The $3.8 billion project was completed and placed into service in 2017.

Most of the protests focused on a small section south of Bismarck, N.D., that crosses under a reservoir on the Missouri River near the Standing Rock Sioux Tribe’s reservation.

The tribe argues it wasn’t adequately consulted in the federal planning process, that construction crosses sacred sites and that the pipeline poses a pollution risk to its water supply. Energy Transfer disputes all those assertions.

The tribe’s demonstrations gained worldwide attention, and thousands of protesters traveled to and camped out in the area along the proposed pipeline route in 2016 and 2017. Police and protesters clashed, with officers using pepper spray and “nonlethal ammunition” to remove demonstrators from federal land. Police said protestors set fires and threw rocks at officers. At one point, police sprayed water on the crowd as temperatures dropped below freezing.

The protests ultimately delayed the pipeline’s completion by several months. Oil began flowing through the infrastructure in 2017. In the lawsuit, Energy Transfer said the delay, damaged property and public relations costs resulted in demonstrable financial harm to the company.

In a 2017 interview with CNBC, Energy Transfer co-founder Kelcy Warren explained why his company was taking the unusual step of suing protesters.

“What happened to us was tragic,” Warren said. “They knew that the things that they were saying about us were inaccurate — things like we were on Indian property, that we didn’t communicate with the Standing Rock Sioux … I mean, it was just crazy stuff that they were saying, and we were greatly harmed by that.”

In the lawsuit, Energy Transfer claimed Greenpeace lied about the company’s work to solicit donations, which the company says it used to organize and fund protests, including “violent attacks on Energy Transfer employees and property.”

“Everybody is afraid of these environmental groups and the fear that it may look wrong if you fight back with these people. But what they did to us is wrong, and they’re going to pay for it,” Warren said.

Warren has been a vigorous defender of his company and the oil and gas industry. Energy Transfer launched a website specifically about the benefits of oil and gas and to counter Greenpeace’s claims.

“You can’t sue a movement”

Greenpeace USA said before the trial that a loss in the North Dakota case could drive the group toward “financial ruin, ending over 50 years of environmental activism.”

Greenpeace argued that Energy Transfer was being disingenuous about the purpose of the lawsuit, which the company denies.

“This case is simple. Big Oil wants to silence its critics,” said Raman during a call with reporters in February. Raman claims Energy Transfer is “abusing the legal system to silence critics” by filing a “Strategic Lawsuit Against Public Participation” (SLAPP) case.

Such cases are usually designed to cost opponents money and force them to spend time defending against the case, according to the Cornell Law School’s Legal Information Institute.

North Dakota is among the 15 states that does not have anti-SLAPP laws, which makes it easier to get such cases dismissed and recover costs from plaintiffs who file them.

Josh Galperin, an associate law professor at Pace University who has been following the case, told NPR earlier this year that the $300 million in damages Energy Transfer sought represented a lot of money for Greenpeace but was not as significant to Energy Transfer. The company generated more than $82 billion in revenue last year.

“I tend to think that their real concern isn’t the financial loss,” Galperin said. “Their real concern is the persistence of the protest — the way it is capable of turning public opinion.”

The jury’s decision was even higher. “The number is just astounding,” says Michael Burger, the executive director of the Sabin Center for Climate Change Law at Columbia University. “One way or another, the effect of a verdict like this, without question, could be to chill speech, to make opponents more reluctant to be vocal in their in their opposition to major projects,” he says.

Before the ruling, Greenpeace USA said such a large financial award to Energy Transfer could threaten to bankrupt the organization. But the group says the message that fossil fuels are heating the climate and hurting people will continue.

“You can’t sue a movement,” Raman says.

More than 400 environmental and other groups signed an open letter to Energy Transfer expressing solidarity with Greenpeace. The letter reads, “We will not allow lawsuits like this one to stop us from advocating for a just, green and peaceful future.”

In recent weeks, the Trump administration has announced its intention to roll back many longstanding environmental regulations and discourage protest across a wide array of social and environmental issues.