CAPTCHA's that stop your robots.
It used to be that comment spam was done to improve the search engine ranking of websites. That motivation has largely gone away with the development of the
"nofollow"tag. Blogs such as "Go To Hellman" attach add
rel="nofollow"to any links in the comment threads. This tells spidering robots not to follow the specified links and tells search engines to ignore the links for purposes of site ranking.
I guess the people who have been leaving spam comments on my blog didn't get that memo. It's annoying to have to delete the comments, especially the ones in Chinese where links get hidden around the periods in "...". I went to the Blogger help pages to see if there's any way to report the abusive commenters (this blog restricts anonymous comments, so there's at least a user profile for every comment). There isn't. What's worse, Google tells you that if you don't remove those spam comments, your site's ranking will be hurt. Then I had my bright idea. I clicked on one of the links left in the spam comment. Then I picked some keywords from the page and plugged them into Google to find the site. There, at the bottom of the search result, was an option: Dissatisfied? Help us improve. Google is asking for feedback. I pasted in the URL for my comment spammer's site, and checked the radio button labeled "The results included spam." I clicked send, and my spammer's site was bound for Google oblivion!
Beware, comment spammers, I'm going to report you!
nofollowmemo either? Some quick googling confirmed my suspicion, China's leading search engine, Baidu, doesn't pay attention to the
nofollowattribute! These comment spammers must be using my blog to juice their Baidu ranking!
Well maybe not. I did a few searches in Baidu. Baidu is probably the worst internet search engine I've ever tried! Baidu gives really stupid results for my vanity search. Baidu doesn't index my blog, my website, or anything I've ever posted. Perhaps China has blacked out the entire Google network, including Blogger, and Baidu doesn't see it any more. Or perhaps "Go To Hellman" has been banned for its post on Qin Shi Huangdi. Baidu has spidered a page from WorldCat that mentions some other Eric Hellman, and has picked up blog mentions of my by John Blyberg and in Dear Author but not much else. It's safe to assume that Baidu's strength is not English-language indexing.
So if Baidu doesn't index my blog, then spammers shouldn't be able to improve their Baidu rankings with comment spam in my blog. There must be some other motivation for the comments.
Another thing I noticed is that Baidu seems to be big on searching for MP3's and PDF's. It ranks sites like Rapidshare rather highly. Maybe Baidu and similar search engines spider websites like my blog to discover the mp3 files, the PDFs, and the video files that Baidu users are really looking for, and the intended audience of the spam comments is these content spiders. My blog has discussed ebooks, piracy and related topics, so maybe the spammers think its a good source for links to content. Who knows?
Another possibility is that the spammers are trying to get bloggers themselves to visit the their sites. "Patrick" from Madras is trying to sell "web templates". It turns out that his site has copied content from another site marketing web templates, which appear to me to be copies of other websites with much of the content stripped out. It's ironic: Patrick seems to be using a template for a web-template selling website to sell web templates.
After a few days, I checked back to see if the website I had complained about had been removed from Google or not. As it turns out, the site actually improved its Google ranking from #5 to #1 in my test search. So much for my career in comment spam scourgedom!