I wonder what's their real agenda with these photos. You can never take what Facebook says at face value. Just like when they say they're only building shadow profiles on you for security purposes.
Forget their intentional use, what about the unintentional use?
"We're terribly sorry this database of photos submitted to prevent revenge porn was accidentally made public. We have fixed the security hole which made this possible, but still intend to keep and expand the database which was exposed. Thank you for your understanding and participation."
Or, imagine a new advertising filter popping up some new advertisements for you: "Have genital warts? Use our cream to make them go away!"
> Given what facebook is and has done, why wouldn't you be suspicious that there is a hidden reason that is beneficial to facebook.
Facebook is in the middle of a PR disaster which sank their stock price because they gave away data to companies that users agreed to give away. Nude photos are probably more sensitive to people than their social security number and bank information -- especially to younger people.
The public outrage that would follow if anything nefarious was happening to voluntarily sent nude photos would be tantamount to destruction of the company. It's not hyperbole -- the whole point of submitting photos to stop revenge porn is to stop the spread of the photos. Anything else would contravene that trust and spark moral hostility.