New to UMS, found other people's folders/pics on it?

[jdx3ds]

So I was browsing my UMS folder on my TV over DLNA and I found a few different folders that weren't mine..someone had a bunch of pictures of stuff he/she baked like cookies and muffins etc and believe it or not I thought this was awesome! I had never thought of the possibility of browsing shared folders/files from people around the world, especially pictures. The problem was only the thumbnails showed up but the pics won't load, maybe a port problem?

My main other question is, how can I add MORE people's files to browse?