The SpaceX and Tesla CEO has taken to social media to warn that social media will soon be manipulated by advanced AIs—if it hasn’t been already. Musk made the alarming warning in two tweets in the early hours on Thursday.

Anonymous bot swarms deserve a closer examination. If they’re evolving rapidly, something’s up. — Elon Musk (@elonmusk) September 26, 2019

In the first tweet, Musk warned that anonymous bot swarms deserved closer attention. Bots are autonomous programs that often attempt to game social media, either by retweeting a specific tweet to promote it across the platform, or to sow disinformation across the platform by making it look like thousands of people are tweeting about the same bit of (fake) news.

Musk says that if it’s found that bot swarms are evolving rapidly—it’s a big signal something is up. It’s unclear if Musk has access to research or information that suggests bot swarms are indeed “evolving rapidly.”

In a follow-up tweet Musk elaborated on his first warning by saying that if advanced AI—which he describes as artificial intelligence beyond the capabilities of regular bots—hasn’t already been applied to manipulating social media, it won’t be long before that happens, though he doesn’t give a timescale.

Musk is often considered a doomsayer when it comes to the topic of artificial intelligence, but his claims today aren’t outside of the realm of possibility. And when Musk refers to an “advanced AI” manipulating social media that doesn’t mean that the AI needs to be sentient and doing so of its own accord. Less-advanced AI could be unleashed upon social media by nation-states with enough resources to game the platforms to spread the information—or disinformation—they want.