Even with this feature in place its just keeps people using internet explorer, maybe some MAC browsers as well from saving things. I know other browsers have no problems, it pops up... you hit OK and then it brings up the save/copy/paste features anyways and ignores the source code on the pages. (Not trying to undermind anything here, just want to point out the facts..)
I think all Mozilla browsers have this since well their from the same base code. Not sure about Opera and Sun's broswers, havent used them in a long while. Either way I agree if someone has a problem with posting copywrited material then others should just call them out on it.
Or disable it when it becomes a problem on this board. As of right now I don't see anyone stepping on anyone elses toes. That could change once some more traffic hits, but for now id say leave it disabled and wait for some problems to arise.