Spam Blog?

Huh? When I went to write that last post I had to enter a verification word to get it to work. "Very strange", thought I, "I've never seen that before". Thinking I'd somehow inadvertently turned on some previously dormant feature of Blogger I clicked on the handy "?" link, only to be told:

Your blog requires word verification

Blogger's spam-prevention robots have detected that your blog has characteristics of a spam blog. (What's a spam blog?) Since you're an actual person reading this, your blog is probably not a spam blog. Automated spam detection is inherently fuzzy, and we sincerely apologize for this false positive.

I'm not particularly annoyed, but I am curious about why this particular blog, which I've been writing in for quite some time, would only now be marked as spam. The only thing I can think of is that I recently created a few more blogs (see right sidebar), all of which cross-link to each other. In the giant relationship graph that is Blogger this creates a tiny, relatively isolated island that's densely interconnected. If I were deliberately trying to boost my popularity/placement that's certainly a strategy which might occur to me.

Anyway, kind of interesting. I've used Blogger's handy form to request that I be validated as "not spam". If you Blogger-validator-folken want to chime in you're more than welcome.