Thanks for asking and your concerns are valid. When we do copy runs and collect photos, we have the owners sign a paper giving OPR the permission to use and display of said photographs in any publication, multimedia production, display, advertisements or internet publication.” Occasionally we will have members ask for permission to enter their work in competition. To do this, we must first ask permission of the owner. As to flickr, we have others that use them to upload their image back to our forum with no problem. We ask that everyone who has their OPR restores on another gallery, remove the person's name from the extension (Example: SmithN_) and also remove the personal information that is found under File>File Info. You may also remove that information by creating a new file and dropping in your restored file, since the personal information will not carry over.
Hopes this helps.