The guys over at Reinvented had a really quick thought that got some gears turning in my head.
XHTML…is valid XML. And valid XML can be tranformed via XSLT into…different XML. RSS is XML.
So, if someone has a well-formed XHTML site, you can publish an RSS feed of their site whether they like it or not. Make an HTTP call, get the XHTML, transform via XSLT into RSS, and publish it. The legal implications should be fun to watch.