bot-trap allows your Web site to automatically ban bad Web robots
(a.k.a. Web spiders) that ignore the robots.txt file. This does
not include Googlebot and other well-behaved robots. The software
requirements are Apache and PHP, but the principles would work with any
Web server setup. The main advantage over other implementations of this
concept is that bot-trap has a manual "unban" feature so that humans can
unban, but robots can't.
