So goes the cartoon-villain tagline of Anonymous, the amorphous collective entity that started as an ad-hoc identity for Internet trolls and pranksters and, in the last year especially, has become an increasingly politicized engine of online agitation and digital "hacktivism."

Last week, Anonymous took on its most challenging adversary yet—itself—when a splinter faction took control of a critical communications hub, and released information that could be used to track down other members of the secretive organization. The incident has revealed just how hard it is to peer behind the curtain and see what, or more importantly who, Anonymous really is.

Through its escalating acts of hacktivism, Anonymous has taken up causes of broadening social and political importance. Starting last September, there was Operation Payback, which unleashed weeks of distributed denial-of-service (DDoS) attacks on the websites of the Motion Picture Association of America and other foes of Internet piracy. Next came Operation Avenge Assange, which briefly brought down Visa and PayPal websites after those companies cut off donations to the embattled Wikileaks. This was closely followed by OpTunisia, OpEgypt, and other operations aimed at helping Arab protestors topple their repressive governments.