They've all been labeled SLAPPs -- Strategic Lawsuits Against Public Participation -- legal actions intended to silence critics and suppress free speech by dragging defendants into costly, time-consuming litigation.

"The process itself is the punishment," said Sushma Raman, interim executive director of Greenpeace, referring to a lawsuit filed against the organization by Energy Transfer, the operator of the Dakota Access Pipeline.

Companies that file such suits argue they are legitimate efforts to protect themselves from defamation or recover damages. Energy Transfer, for its part, told AFP it supports "the rights of all Americans to express their opinions and lawfully protest."

- Abusive process -

The term "SLAPP" was coined by two University of Denver professors in the late 1980s, and Washington state became the first to pass an anti-SLAPP law in 1989.

Media lawyer Thomas Burke, author of the book "Anti-SLAPP Litigation," told AFP that SLAPP suits make up "80 percent or more of the big lawsuits" against the media and environmentalists.

He worked on the largest anti-SLAPP settlement in US history, defending the Center for Investigative Reporting against a lawsuit by Planet Aid over a Mother Jones report about its activities in Malawi.

The case was dismissed in 2021 under California's anti-SLAPP law, with Planet Aid ordered to pay nearly $2 million.

Then-private citizen Trump once sued a book author and publisher for $6 billion over claims about his net worth. The lawsuit was dismissed, but without an anti-SLAPP law, the defendants couldn't recover legal costs.

Trump later bragged, "I spent a couple of bucks on legal fees, and they spent a whole lot more. I did it to make his life miserable, which I'm happy about."

The president is currently suing an Iowa pollster over an incorrect prediction, alleging election interference.

Kevin Goldberg of the Freedom Forum told AFP that while the US Constitution enshrines free speech protections, many people don't realize they can still be sued -- along with the significant financial burden, time commitment, and stress that come with it.

- Anti-SLAPP laws -

Today, 35 states and the capital Washington have anti-SLAPP statutes.

To proceed, plaintiffs must overcome significant legal hurdles, such as proving their case can withstand a First Amendment defense or demonstrating "actual malice," that the statements were made with reckless disregard for the truth.

But no law yet exists at the national level.

"So if plaintiffs who just want to shut organizations want to sue, they're going to do their level best to get into federal court," said Burke.

A key feature of anti-SLAPP laws is that they require plaintiffs to cover defendants' legal fees, acting as a strong deterrent against frivolous lawsuits.

"Real people are affected by SLAPPs just as much as anybody else," said Goldberg explaining that most cases fly under the radar, targeting ordinary individuals -- from those posting negative reviews to local bloggers exposing shady business practices.