The volume of junk e-mail sent worldwide dropped drastically today after a Web hosting firm identified by the computer security community as a major host of organizations allegedy engaged in spam activity was taken offline.

The servers were operated by McColo Corp., which experts say has emerged as a major U.S. hosting service for international firms and syndicates that are involved in everything from the remote management of millions of compromised computers to the sale of counterfeit pharmaceuticals and designer goods, fake security products and child pornography via email.

two Internet providers cut off MoColo's connectivity to the Internet. Immediately after McColo was unplugged, security companies charted a precipitous drop in spam volumes worldwide. E-mail security firm IronPort said spam levels fell by roughly 66 percent as of Tuesday evening.