Another problem with zonker's proscription is that it argues that mirroring/caching should require permission (be opt-in) but the web would be a much less beautiful place if that were the case (think of the problems Google or the Internet Archive would face -- or even IE or Netscape and caching).
Instead, I would argue that sites like Slashdot should:
- Provide caches of the first page or movie or image on which they are reporting for pages that do not have advertising (but leave direct links for very large sites and pages supported by advertising)
- Keep links off that page pointing to the real site; and
- Remove the caches after a limited (short) time.
That way advertising supported sites get the maximum amount of advertising, but sites not supported by advertising on the about to be slashdotted pages are not overwhelmed. I would not require permission for linking or caching. That permission is implicit in the posting of a publicly accessible web page. Prohibiting linking in order to deal with slashdotting is not a sensible argument.