Charles Johnson reports that referer spam attacks are up:

Behind the scenes, there is a pretty amazing swarm of robots hitting our Most Recent Referrers page tonight, using zombie servers (servers infected with a previous virus that leaves a back door open) with a range of proxy IP addresses, many in China, to try to plant URLs among our referrers that link to the usual dreary list of illicit pharmaceutical products. This kind of idiot spamming is a constant annoyance, but tonight’s robot swarm is extraordinary for its sheer volume.

That was the problem that took this site offline for a bit over an hour yesterday, and resulted in my moving the referer list behind a post form, accessible only to the author of a blog. I guess a new assortment of bots is out there being played with.