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The public relations executive from Birmingham, Michigan, was fed up with so-called comment spam. Returning from a weeklong vacation, he found a slew of comments on his blog that had nothing to do with communications: They were posts from spammers promoting gambling sites and prescription drugs.

"I'm not in this to spend hours a week cleaning up the mess spammers leave behind," Shinbach says. Ironically, the surge in spam to his blog coincides with a decrease in spam to his inbox: Shinbach says that his desktop antispam software and his ISP's spam filters together block about 95 percent of junk e-mail sent to his account.

Shinbach is one of many who are starting to fret more about spam on blogs, instant messages, and cell phones than about traditional unsolicited e-mail--at least in part because old-style spam appears to be losing some momentum. While the volume of junk e-mail continues to mount, it stopped growing at double-digit rates last year. Many ISPs and e-mail providers claim that they blocked more than 90 percent of unsolicited commercial e-mail.

"Spam filters have gotten so good, a properly managed filter can turn the sting of spam into a minor inconvenience," says Richi Jennings, analyst at Ferris Research, a market research firm that specializes in messaging.

In contrast, other forms of spam--prompted by the rise of new messaging media--are just gathering steam.

"Many spammers are reinventing themselves," says Paul Judge, chief technical officer for messaging security firm CipherTrust. "Whatever messaging paradigm that consumers are using, spammers will be right there."

Comment spam is one of the new forms. Another is the splog--short for spam blog, a blog that is created purely for marketing purposes.

Some spammers create dozens, if not hundreds, of splogs that link to the spammer's Web site, helping to artificially inflate its ranking in Google and other search engines. Another type of splog seeks to get visitors to click ads that link to sites that pay the splogger referral fees.

Derek Gordon, spokesperson for Technorati, a blog-resource Web site, estimates that 10 to 15 percent of the 70,000 new blogs created daily are splogs. CipherTrust's Judge says he expects that percentage to grow in 2006. These shady blogs have become a serious headache for companies, such as Google, Microsoft, and Yahoo, that offer free blog services. Many are fighting back with software designed to identify splogs, similar to programs that identify e-mail spam.

Bloggers plagued by comment spam can also get help from sites such as SplogSpot and Splog Reporter, which collect information on such content to help network administrators filter it out.