Hey, you violated your own rule about not feeding the trolls! :-)
I also don't allow anonymous ftp. I also don't allow ftp from the internet. Service port 21 doesn't exist on my firewall linux box.
If this is showing up, it's because wanna-be admins don't know squat about security. It happens with all os's. You wouldn't believe the number of people running windows that share their hard disk via DSL. Idiots will be idiots.
/john