you cannot prevent anyone that can see content to copy it  Usually code that prevents right click is javascript, all the visitor needs to do is to disable javascript. Same for images.. if the browser displays the image, it is already copied to the client pc.. someone can just grab it from the cache

i would invest your time in other things ... (just my 2 cents though....)

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If you'd like to do this with a module, there's a Page Protection module available (Snowcovered) and it's quite modestly priced. 

I agree that the level of protection offered is minimal, but a client absolutely had to have this on a site, and this module works.