How does a proxy server violate copyright? Maybe I don't understand what exactly Genius is doing, but how is this different from say blocking ad servers in my hosts file?
And if Genius is hosting the page that's annotated, that's one thing. If they're simply proxying it on demand and adding annotations, then I don't see how it violates copyright unless every proxy server violates copyright.
This is a key distinction that separates proxies from caches and archives.