Greenpeace is among the most well-known environmental organizations in the world, the result of more than 50 years of headline-grabbing protest tactics.

Its activists have confronted whaling ships on the high seas. They’ve hung banners from the Eiffel Tower. They’ve occupied oil rigs. A (fictional) activist even sailed with Greenpeace in an episode of “Seinfeld,” in hopes of capturing Elaine’s heart.

Now, Greenpeace’s very existence is under threat: A lawsuit seeks at least $300 million in damages. Greenpeace has said such a loss in court could force it to shut down its American offices. In the coming days, a jury is expected to render its verdict.

The lawsuit is over Greenpeace’s role in protests a decade ago against a pipeline near the Standing Rock Sioux Reservation in North Dakota. The pipeline’s owner, Energy Transfer, says Greenpeace enabled illegal attacks on the project and led a “vast, malicious publicity campaign” that cost the company money.

Greenpeace says that it played only a minor, peaceful role in the Indigenous-led protest, and that the lawsuit’s real aim is to limit free speech not just at the organization, but also across America, by raising the specter of expensive court fights.