DenyHosts: Remove / Delete an IP address

原來 Ubuntu 裡面有一個 service 叫 DenyHost, 會主動更新 /etc/hosts.deny
相關文章如下

http://www.cyberciti.biz/faq/linux-unix-delete-remove-ip-address-that-denyhosts-blocked/
http://denyhosts.sourceforge.net/faq.html