I regularly shoot equestrian events, show jumping etc and I'm sick of seeing so many of my pictures (and those of other photographers) screen grabbed and used on Facebook and other sites.
I use a bold watermark with my name and the year diagonally across the middle ie "(c) Dave Gaskell 2013" but people don't care. It's just so easy to take a screen shot and upload it to Facebook that so many people don't give the morals of doing so a second thought.
I challenged one Facebook thief after spotting almost fifty of my pictures from 2012 on her page without a single purchase (ever) and she said "Well it's free advertising for you." To which I replied "The only thing it advertises and encourages is other people to do the same!"
For 2013 I'm going to add the text "Duplication of this image is theft" to the watermark. Afterall who wants to see pictures with the word "theft" on their Facebook page?
I'm also experimenting with a moving obscurer such that part of the picture is always covered as demonstrated here, www.davegaskellpictures.com/.. ./
This way people can see all parts of the picture but only ever three quarters at any one time and that's all they'll get if they take a screen shot. Ok, so they could take two screen shots and merge them but it puts a time consuming obstacle in their way.
In the examples in the above link I've created them by producing a gif animation file of four frames and it took some time. My website provider has agreed to letting me upload an animation gif of just the black rectangle moving round and this will be overlayed onto my event pictures. I've run the idea past a few of my regular trusted customers and they mostly think it's a good idea and are happy to see it used, after all they're the ones who are effectively paying for those that get pinched.
Wouldn't it be neat if Aperture allowed us to export our pictures protected in this way with a moving obscurer.