Took me a little while to understand what you were trying to say. You are implying using the @ trick talked about on a framed page that shows the actual content of another site. So the user actually thinks they are visiting CNN or whatever, when in actuality they are visiting some other site, but getting the content of CNN. The framing page could do something malicious or annoying and most users would assume that CNN was doing it.
Maybe we need to approach the w3c with a proposal for a way of busting frames for the next version of html (actually xhtml)! Seems to me that a site out to opt-in to frames rather than opt-out (or as currently, opt-accept-any-site-that-wants-to-frame-me).