Here's a note I've never seen before:

Scripting Abuse Detected! on Today (Sunday, 08 July) at 10:44pm

Abusing user ID (Real Name): Guest -> ()
Abuse detected from IP: 8.7.22.195
Blocked script in Url data: ghost9_10" gping

Radified Community Forums, The Guardian

Not sure exactly what it means. The Guardian is a feature-set that comes with YaBB v2.1. It's setting are configured to default.

The email I received, as you can see, doesn't provide a user name. Maybe I'll check the error logs.

Here's what the error log says:

Yesterday at 10:44pm Guest
(8.7.22.195) You tried to use scripting in the url or form input, which is not allowed!

Looks like a guest tried to do something naughty with a script.