This comment posted (and deleted) by Reddit user WonkoTheLucid shows why photographers need to make sure their websites are secured properly:
My friends wedding photos were posted with watermarks on a photo reprint site for sale. The prices were a bit outrageous. Another friend who does web design clued me into manually entering the photo address to display a full resolution photo without a watermark. I wrote a script and downloaded 500 free high res photos. Burnt many dvd copies and mailed them to a bunch of random people who were at the wedding.
If you’re a professional photographer that lets clients review proofs online, make sure the high-res, non-watermarked versions of the photos aren’t accessible by simply changing a portion of the URL.