In May, LinkedIn suspended the account of Republican presidential candidate Vivek Ramaswamy after he posted several climate-related campaign messages.

In one message, Ramaswamy asserted that "fossil fuels are a requirement for human prosperity," and in another, he wrote that if adherents of the "climate religion" really cared about the climate "they'd be worried about, say, shifting oil production to places like the U.S. and China."

"Big Tech election interference has begun," Ramaswamy said.

LinkedIn (owned by Microsoft) backtracked under pressure and reinstated his account. But the episode highlighted the ways in which social media companies are expanding their "content moderation" of "climate misinformation" — with potentially far-reaching consequences across the political spectrum.

In another incursion into the presidential race, YouTube attached a "Context" note to a June 5 interview of Democratic presidential candidate Robert F. Kennedy Jr. in which he discussed his views about climate change with Canadian psychologist Jordan Peterson.