Another example after the trick to reveal 'hidden' passwords:
In Flickr, when the author put a right restriction, Flicker disables the ability to right-click and download the image (try it here, *View background image): you end up with a 1-px blank image.
So fire up the Element Inspector, that should highlight that "protection" zone:
And just delete this tiny div! (actually, the link to the image <img src=... /> is right below).
Now View image is available again :-)
By the way, in up-to-date versions of Firefox, you can bypass right-click protection by pressing the shift key at the same time, like in this website.