Great question Caroline and one that I ask myself all the time as I am very active on social media sites. Bottom line: if you put it out there, expect it to be stolen. Try a reverse Google Image search and you'll be blown away. Eastern European countries constantly steal my work but how do I go after them? Russia is #1 in theft of my work. People ask me about watermarking my images. I used to but recently stopped as it takes less than 30 seconds in PS with Content Aware to remove them so what is the point? On the other hand, most people who attend my workshops first find me on social media - so it is a double-edged sword. Bottom line, I put it out there.