These days, I get an email about once a month or so from Flickr telling me that my private photos are over some usage limit and then threatening to delete them unless I sign up for their paid service.
I briefly tried to find my private photos so that I could review/delete/public them, but it wasn't obvious in the interface, so I gave up.
Given that they have been sending me this email for what feels like a year now and they haven't done anything, I'm just going to keep ignoring the email.
If they delete the photos, oh well. If not, oh well. Just seems like a super weird way to deal with people.