FRAUD ALERT. Let me give you a warning.
I look at all of this much like I do a home security system: If the Bad Guy is determined enough, you're not going to keep him out. But for the casual thief, it just makes your neighbor's place more appealing.
On the watermarks I've used in the past (similar to this one I just swiped of the interwebs), it all depends on the picture. I imagine it would take a lot of work to Photoshop this image, but of course I could be wrong.
I look at all of this much like I do a home security system: If the Bad Guy is determined enough, you're not going to keep him out. But for the casual thief, it just makes your neighbor's place more appealing.