[lucaspiller]

Facebook already uses facial recognition to suggest tags on photos, so I don't think false positives are that much of an issue:

https://www.facebook.com/help/122175507864081

You other points are true though, and I guess a lot of these type of photos don't always contain faces.

[danso]

I'm not as heavy of a FB user as I was 5 years ago, but my impression was that false positives were at an acceptable threshold, but not nearly a solved problem. And the face recognition tech was heavily augmented by social data, such as the fact that me and a friend were both partying at the same place on the same night and that we had just 3 days ago posted and tagged photos of each other.

That secondary data does not exist reliably in the context of revenge porn videos that go viral. Nevermind that the penalty of a false positive -- which would presumably involve exposing the user to a bit of random porn -- is substantially higher than it ever is with mistagging friend photos.