A significant rise in the global volume of spam in the past two months
has security analysts worried that bot nets are increasingly being used
by spammers to stymie network defenses erected to curtail bulk e-mail.

Estimates of the magnitude of the increase in junk e-mail vary, but
experts agree that an uncommon surge in spam is occurring. On the low
side, Symantec, the owner of SecurityFocus, has found that average spam
volume has increased almost 30 percent for its 35,000 clients in the
last two months.

Story continues at securityfocus.com