Blog search engines are struggling to block the increasing number of blogs that contain spam, commonly known as splogs.
Mark Cuban, the owner of a blog search engine IceRocket, said on Monday that spam occurs in "monstrous proportions" in blogs. Google's free Blogger service is a common source of splogs and spammers are automating the creation of blogs using this service, said Cuban in a blog posting.
"Blogger is by far the worst offender," he said. "It's fast, it's easy, it's free and it can be automated. So blogs are coming at us left and right. We are killing off thousands a day, but they keep on coming."
Cuban warned that splog detection algorithms are not perfect, so innocent bloggers are increasingly likely to find their sites blocked, particularly if they use the Blogger service.
"If you are an individual blogger whose blog is hosted on blogspot.com, every day the chances of you being excluded from icerocket.com's, and other search engines' indexes increases. It's not just blogspot.com, pretty much 90-plus percent of blogs hosted on .info sites are splogs as well," Cuban claimed.
It is not only blog postings themselves that may contain spam, but also comments on blog postings. Spammers often post links in blog comments to raise the search engine ranking of their Web site.
Search engines Google, Microsoft's MSN and Yahoo, along with blog tool vendor Six Apart, responded to this threat in January by creating a new attribute for HTML hyperlinks. All three search engines have agreed that if their search bots see the attribute, rel="nofollow", the associated link will not get any credit when they rank Web sites in search results.
A number of blog software makers have agreed to support this attribute, according to a Google blog posting.
Although the nofollow attribute will help reduce the rating of splogs on Google, Cuban accused the search company of not doing enough to tackle splogs on its Blogger service: "Google seems to be working hard to adjust their relevancy indexes to exclude splogs from having influence on search rankings, but they don't seem to be doing anything more than removing reported splogs. Kind of like going after the zombies one at a time with a shovel. Can we get some help on this Google?"
Google did not respond to Cuban's comments in time for this article.