Jogchem de Groot a.k.a bighawk is a member of Hackweiser which is an underground hacking group and hacking magazine founded in 1999.
He claims that he was not involved in the Cryptome attack.
Uses gnuchess to beat opponents in Yahoo chess
http://dsr.segfault.es/stuff/website-mirrors/pHC/old/bighawk.txt
https://en.wikipedia.org/wiki/Hackweiser