The Italian Honey Project

Security researchers have discovered another botnet that uses Twitter as a command and control channel.Malware-infected drones in the Mehika Twitter botnet, active in Mexico this summer, take instructions from a Twitter account maintained by hackers instead of conventional command and control servers. The use of Twitter as a botnet command channel was first detected in August 2009 before similar techniques were applied to abuse Facebook profiles as command channels a few months later in November.

via Mexican Twitter-controlled botnet unpicked • The Register.