
Not to mention the fact that it's only really static content that archive.org can archive properly. From their FAQ:
How do you archive dynamic pages?
There are many different kinds of dynamic pages, some of which are easily stored in an archive and some of which fall apart completely. When a dynamic page renders standard html, the archive works beautifully. When a dynamic page contains forms, JavaScript, or other elements that require interaction with the originating host, the archive will not contain the original site's functionality.
Admittedly, archiving dynamic web content seems like a pretty intractable problem...
There is no opinion so absurd that some philosopher will not express it. -- Marcus Tullius Cicero, "Ad familiares"