The difference between claiming copyright and actually having it
Since posting on the web is so easy, and so common, it became routine for these copyright notices to be applied. Even libraries do it. Of course copyright only belongs to the creator of a piece, never to a library, or, well, anyone else. And once copyright expires, the work goes into public domain.
If you're afraid of posting a photo from 1908 for fear of copyright violation, it's probably better that you don't. But since that photo from 1908 is public domain, it's probably better than you don't tell someone the "facts" about copyright that you don't know.
I wish I could stop people from claiming copyright on things they don't own, but I can't. So I wrote this. I hope this helps.
Posted by Brad Hall