This may seem like a realization of some science fiction stories.

It has been reported that robots from MSN have gone amok on the cpantesters site. Microsoft sent 20-30 bots every few seconds, ignoring the robots.txt file. When cpantesters began sending 403 error replies to requests from offending IP's, they were still bombarded with requests.

http://blogs.perl.org/users/cpan_testers/2010/01/msnbot-must-die.html
http://www.h-online.com/open/news/item/Microsoft-bots-perform-denial-of-service-on-Perl-Testers-906094.html

http://www.cpantesters.org/robots.txt