San Bruno, Calif.—IronPort Systems, an Internet gateway security provider, this week announced current statistics from its Threat Operation Center about the worldwide increase in image spam. Worldwide spam volumes increased from 31 billion messages a day in October 2005 to 61 billion messages per day in October 2006, an increase of nearly 100%. Image spam reached a new high of 25% of total spam volume in October 2006 compared with 4.8% in October 2005, an increase of 421%. Because of the increase in image spam, the average spam message size has grown from 8.9KB to 13KB, a 46% increase. Bandwidth used by spam increased from 275 terabytes per day in October 2005 to 819 terabytes per day in October 2006, an increase of nearly 200%.