Honestly as a total Noob to photography well I don't see why anyone would really want to take my photos and I am not saying that anyone has or would but really I guess at this point I would be kind of flattered that someone wanted it that much that they took it and used it somewhere else!!!
The bottom line is though that if you don't want them stolen don't post them on the net. Even if they do get taken what are the chances of you EVER finding out that someone has them? Really?!
Its a common thing to heist a pic from the net, your looking for something special for a card or a flyer and you hit images on your local browser and poof its one, two, three, download...oops I just infringed that Copyright law. I've done it and I am sure that most EVERYONE here at one time or another has done it also. Have I taken one and used it to gain Money or fame...No, but it would be ohhh so easy to do.