I'd recommend that wherever you suck it from, you get permission. I got permission to poll daily using rsync from the master site for a private archive on stonehenge.com, so that I can mirror it down to my laptop on a regular basis. We coordinated it so that it'd be during a traditionally low-usage time period.

And I'd definitely recommend rsync over FTP. Rsync just plain rocks. I'd be happy to talk to your admins to let them know that rsync servers are no less secure than FTP servers.

-- Randal L. Schwartz, Perl hacker