Last week, Akonix issued a press release discussing the fundamental differences between Spim (spam sent via instant messaging systems) and e-mail-based spam. Understanding the differences between the two is important because the method by which each of these problems is solved is fundamentally different.E-mail-based spam is sent through more or less conventional means: an individual simply broadcasts a large number of messages to a list of e-mail addresses. While some worms can be used to hijack unsuspecting users\u2019 systems to broadcast spam, the method by which most spam is sent is fundamentally no different than one individual sending e-mail to another.Spim, as noted by Akonix in its press release, is generated primarily by worms and other unwanted software. The software will infect a machine and turn people on your buddy list - people you implicitly trust to send you instant messages - into spimmers without their knowledge or consent.Spam filters that review the content of incoming e-mail are generally quite effective at blocking the vast majority of spam. Spim eradication systems, on the other hand, need to focus on the worms and other software that generate spim. In other words, spim must be addressed much closer to its source than spam in order to effectively stop the vast majority of messages from getting through.It is highly unlikely that spim will ever reach the level of problems caused by spam, for a variety of reasons. That said, it\u2019s important to address the problem now with appropriate technology to block spim-generating software before the problem gets out of hand.