Lately, I have been getting a lot of Cyrillic comment spam. It tends to slip past Akismet, as well as the built-in WordPress spam filters. They’re always spam, never legit comments. (As this is an English-language blog, there wouldn’t be much point for somebody to post non-English comments, anyway…)
It has been a minor annoyance for me, since I get a few every week and have to manually remove them.
Fortunately, Jeff Starr (of Digging into WordPress fame) has come up with a solution. Apparently you can put Unicode characters into the WordPress comment blacklist…which of course would include Cyrillic characters. I don’t know why I didn’t think of that to begin with, it’s so simple.
Anyway, his post includes several characters you can copy and paste into your blacklist.
10 Characters for Your WordPress Blacklist [Perishable Press]