Leveraging social networks to fight spam

The amount of unsolicited commercial e-mail-spam-has increased dramatically in the past few years. A recent study showed that 52 percent of e-mail users say spam has made them less trusting of e-mail, and 25 percent say that the volume of spam has reduced their e-mail use. This crisis has prompted proposals for a broad spectrum of potential solutions. The objective of the various proposed legal and technical solutions is the same: to make sending spam unprofitable and thereby destroy the spammers' underlying business model. Achieving these goals requires widespread deployment and use of antispam techniques. To gain user confidence, a prerequisite for wide deployment, the tool must be accurate, user friendly, and computationally efficient. The authors describe a technique, predicated on recognizing the unique characteristics inherent to social networks, that simultaneously achieves all these requirements.