No picture is ever seguro from theft, but I will give you a tip of advice. If you draw like I do, or similar, take a crappy picture. Well, take it well enough that people can see and enjoy what it is, but take it in a way that it is so imperfect that no one would want to steal is. Such as tilting the camera, sticking your hand in the corner, adding a glare, etc. I hope this has helped.
