Copyright - spun off from POTD
An observation: In every case where I have been contacted by publishers for prints, they always want an original, preferably RAW with authors name embedded in EXIF. This generally insures that they are buying from the originator.
Photos published here, and on other boards, are (hopefully) size reduced jpeg's, so not suitable for copy publication. Of course there is no guarantee that someone will not "borrow" and image, but it will be difficult to resell in this form.
Note: You can also enter artist name and copyright as part of the EXIF info.