The Writers Guild of America East has blasted Peter Thiel for attempting to put Gawker Media out of business by bankrolling Hulk Hogan’s lawsuit.

The guild has also demanded that the Silicon Valley billionaire reveal any other similar legal actions against the digital media site.

“It is imperative that the public know the extent of his efforts to silence the press,” the union said. The demand was issued Thursday, two days after the first report that the tech billionaire helped support Hogan’s suit against Gawker.

“Peter Thiel has all but confessed that his primary objective is Gawker’s demise,” the WGA East said. “Plutocrats already have outsized power in this country, and we cannot allow them to use their vast fortunes to silence media companies.”

The WGA East was successful last year in unionizing the 100-member Gawker staff, which ratified its first contract in March.

“We cannot let Peter Thiel heedlessly destroy one of the most original, intrepid digital media companies in modern journalism — regardless of whether or not we like everything that gets published there,” the guild said. “It is imperative that the public know the extent of his efforts to silence the press. We call upon Peter Thiel to reveal all of the lawsuits he has funded.”

Hogan won a $140 million verdict in March in a defamation suit against Gawker Media after it posted parts of a sex tape showing Hogan with a friend’s wife. A Florida judge upheld the verdict on Wednesday.

Thiel confirmed this week in an interview with The New York Times that he had paid $10 million in legal expenses to finance several lawsuits brought by others, including the Hogan lawsuit, against Gawker Media. The newspaper said he was driven to mount a clandestine war against Gawker due to a 2007 article published by Gawker’s Valleywag blog, headlined “Peter Thiel is totally gay, people” and articles about his friends that “ruined people’s lives for no reason.”

“It’s less about revenge and more about specific deterrence,” Thiel said in the interview. “I saw Gawker pioneer a unique and incredibly damaging way of getting attention by bullying people even when there was no connection with the public interest.”