it doesn't have to be a visible link either.
I log bad bots thru a hidden href
http://dragonflycms.org/ (view page source and look at the bottom for: trap_crawler
You will get logged in
http://dragonflycms.org/trap_crawler/blacklist0.dat (unknown agents)
http://dragonflycms.org/trap_crawler/blacklist2.dat (know agents but probably malicious)
It seems to work so i gonna start a banning system with it
