You know there's a root index file at http://cdn.media.ccc.de/INDEX
Also you should use the CDN to redirect to the correct mirror
Re:30C3 Recordings
by hydrogen18 on Monday December 30, 2013 @07:06PM
(#6988007)
The web server returns redirect responses to mirrors that wget follows.
Just to clear this up: cdn.media.ccc.de is the new name for ftp.ccc.de. It was renamed because it does not actually serve FTP anymore, since HTTP can be load-balanced a lot better.
https://gist.github.com/hydrogen18/8185934