By bankrolling Hulk Hogan's high-profile lawsuit against Gawker, Thiel drove the media company to bankruptcy. Thiel called his actions "one of my greater philanthropic things that I've done." Thiel's critics on the other hand, have called him a secretive billionaire waging a shadowy war to suppress the free press -- or at least the part of the free press that publishes stories he doesn't like.

"This contradicts the messages [Zuckerberg] has been sending—about Facebook being open, inclusive, and unbiased," startup advisor and Stanford professor Vivek Wadhwa told Mashable.

Thiel, an ardent Trump supporter, was also part of a group of Facebook representatives who met with members of the conservative media to address accusations of bias in the social network's Trending Topics section.