In this case, Facebook's 99-page user policy. The results, embedded in the story, are worth a listen. This is is some serious sci-fi shit compared to ChatGPT.
They make cool stuff, but they are ultimately an advertising company (as in that's their main source of revenue). So by all means enjoy the cool stuff, just proceed with caution and of course assume nothing is permanent!
I have a feeling this experiment would sooner get the axe than have ads injected. There was initially a waiting list, but just a few days in it was completely open to the public.