The only way that an embedded copyright or other form of copyright is going to work is if you plan to sue the person who has stolen.   I workded for many years as a graphic designer in an ad agency in San Franisco and we had someone steal the " Mock Up " that we did in our proposal to them. We found it in a magazine, and were able to sue.  I dont know if it works differently or not for work done for a person that is stolen or not.........But I do know that the only difference that copyrights or watermarks make is in a court of law.  I just yesterday found an image on there by Donakuka that was dedicated to me.  I saw no mention of her name as the artist, altho the Title included my Rosity name.   I decided to save the file to my hard drive so I could check it on rosity and I found that the name of the .jpg included the Title and DonaKuka's name as the artist.  Confusing at best......