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
Post and repeatedly endorse generally inoffensive content that for some reason violates Facebook’s ToS, such as the comic book cover of Captain America punching Hitler or the Led Zeppelin album “Houses of the Holy”