I can see it making it harder for people but I was only asking because someone I know on facebook and they post here sometimes had photos stolen this week and the people who stole them managed to remove his watermarking.
the other thing is to make sure what ever picture you put up on the web is to change the PPi in the image size some where between 50 and 72 this will allow people to see them on screen and print at a postcard size but anything biger becomes unusable , plus it speeds up the picture up load and if on your website speeds that up to