By the letter of the law you are correct, with particular reference to "distribute your work". The work of many of Toronto's best photographers such as Boris Terzik, and Phil Marion are posted in forums around the world. There's likely a few thousand photos here on UT that are copyrighted. My future renders over the years have been re-posted many times, however I personally have only objected when they have been lifted without permission for use on a business site (usually real estate).
I'm not a lawyer but I believe that every photo here, by our amazing pool of talented pool of photographers, has copyright "vested" despite no specific use of the copyright symbol, watermarks etc. I'm only aware of one UT contributor who has indicated that no re-posting of photos without permission is allowed.
So by the book, the photographer's permission should be sought. I'm sort of suprised that something like "copy link location" can't be disabled if a photographer explicitly doesn't want his or her photo posted outside of Flickr and other such forums.
Every forum I am aware of requires a proper link to the photographer to accompany the post. UrbanToronto states "When posting copyrighted material please include source, author and a link to the source.". If however UT has in fact a zero tolerance policy for posting photos such as this, the MODs can delete it, or I'll do it myself.