No Such Weblog

After last night's blog spam attack has painfully exposed the lack of rate limiting in the version of movable type that I was using (and the lack of resource limits on my web server), I've gotten a little paranoic about my web server logs. One particularly remarkable feature that only seems to show up quite recently consists in "random" user-agent strings; there are numerous queries of this kind from a relatively small number of IP addresses, apparently DSL-connected machines.

It's relatively obvious that some kind of robot is behind this -- does anyone have an idea what's going on here, or does this sound familiar in any way?

Later: Things should be somewhat more robust now. Resource limits are in place, the back-end has moved to MySQL, and blog items are automatically closed for comment after seven days.