It seems like there might be all kinds of copyright problems when mirroring IA. With Wikipedia, everything is licensed under Creative Commons. But IA is a copy of all kinds of websites with all kinds of licenses. It's a big effort for them simply to remove content that companies rightfully request be removed.

Much (all?) of IA content already has metadata for licensing, e.g. out-of-copyright books. It should be legally ok to mirror the CC and public domain content, but I don't know if there's an easy way to extract a dump or torrent.

Check out robots.txt -- most companies use it (in this case) because it's easier than dmca takedowns.