I webmaster for my wife's photography site. I just tried about eight different plugins to help protect her photos before trying this one.
It protects the photos from 90% of the problem. Right-click is not disabled on the site, so users can still "open link in new window," for example. It is discreet and polite and easy to use.
This plugin does not come up in a search for "photo protection." The SEO could use a little attention.