A new report from e-mail vendor Postini indicates that spam -- or unsolicited commercial e-mail -- is worse than it has even been. According to the San Carlos, California-based firm, the percentage of spam grew by 59 percent among the 70 billion e-mails that Postini processed from September to November alone, bringing the level of junk e-mail to a striking 91 percent of all e-mails sent. According to Postini, total levels of spam have risen by 120 percent in the last year. And, just as bad, spam is growing more complex.

Some of the latest problems include complex image spam and Office spam (in which malicious code is embedded in attached Microsoft Word, Excel, and PowerPoint documents). Robot networks, consisting of hundred and even thousands of computers hijacked by malicious code to send out massive amounts of spam, account for much of today's Viagra, drug, and porn offers. These botnets are often said to be controlled by organized criminal groups, not just rogue spammers.