Their librarian is a weirdo. And that's part of the problem, it's hard to defend against random insanity like that. It always catches me off guard. What a bizarre thing for a librarian to be angry about.
Madness string 100364
The vast vast majority of defcon ctf is reversing and binary exploitation. Usually with some exotic shit you've never heard or dreamt of. One year they gave everyone some binaries compiled with middle endian, another year they gave everyone some playstations and you had to hack through the game.