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
Hopefully I'm not walking into a trap:
What's a headmate? In my brain it fits in the sentence but I don't know what it means
A headmate is another person who I share my body with, having multiple people in one body is called plurality.
Oooh, gotcha! Have fun!