The FlickrFind is one of our most popular ongoing features at Majikthise. Here's how FlickrFinds work...
All the FlickrFinds are from users who enable the "blog this" function on their accounts. Users choose who can blog their photographs--just themselves, their contacts, or any Flickr user. All my FlickrFinds come from users who opt-in and allow any Flickr user to blog images from their photostreams.
I assume that users are turn on the "blog this" feature because they want their photos to be blogged.
Of course, FlickrFinds automatically include attribution and a link to the user's photostream.