Then CC-license your content with the most restrictive CC version (non commercial, no derivative works, attribution required). That’s essentially what Pinterest's "anyone can repost anything that anyone has posted" sharing style is, anyway.
By using the full "all rights reserved/copyrighted" status, you’ve essentially told Flickr and any users viewing your photos that any use of that photo must go through you first.
What if I’m a professional photographer who doesn’t want my photos re-posted everywhere to, in essence, help Pinterest gain users make money? (Rhetorical, by the way; not a pro photographer and most of my photos are under the least restrictive CC-BY license. I personally think photographers could stand to get a lot more exposure via Pinterest.)
By using the full "all rights reserved/copyrighted" status, you’ve essentially told Flickr and any users viewing your photos that any use of that photo must go through you first.
What if I’m a professional photographer who doesn’t want my photos re-posted everywhere to, in essence, help Pinterest gain users make money? (Rhetorical, by the way; not a pro photographer and most of my photos are under the least restrictive CC-BY license. I personally think photographers could stand to get a lot more exposure via Pinterest.)