Dropsitenews published a list of websites Facebook uses to train its AI on. Multiple Lemmy instances are on the list as noticed by user BlueAEther
Hexbear is on there too. Also Facebook is very interested in people uploading their massive dongs to lemmynsfw.
Full article here.
Link to the full leaked list download: Meta leaked list pdf
I'm more concerned about the non-consensual scraping causing excess load on the servers. The taking of content without license to train their energy-wasting autocomplete that is being used to for little commercially but to try to cheapen labor and pocket the money is a problem too. But I hate having servers impacted by their bullshit.