Bloggers are quite aware of the problem of comment spam: automated bots that seek out weblogs and leave inane comments that contain links. The goal is to improve the advertised site’s Google PageRank, in addition to providing a few impressions on the weblog.
We’ve had this problem under control for several months using a technique called HashCash. We also format all links in comments with the rel=’nofollow’ attribute, which prevents Google from using the link in its PageRank calculations. (Yet spambots still visit us. Go figure.)
Recently, some spambots has broken HashCash. So, we’ve added a new layer of shiny anti-spambot coating: the Obvious Question. If you’re leaving a comment (please do!), before you submit the comment form you’ll need to answer an Obvious Question. The answer is even provided, in case what’s obvious to us isn’t obvious to you.
In general, we hate the idea of inconveniencing real contributors in order to better manage spam. But the ratio of spambot postings to real postings is running well over 1:1. The Obvious Question attempts to solve the problem in the least intrusive way.
posted April 22, 2006 by admin
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