US comment spam in blogs … from K-12 schools?

I was going through my MT-Blacklist logs like I do every day and I noticed something absolutely amusing. If you trace the IPs that the logs come from, the majority of them come from Europe or Asia. This is not unexpected since spammers are being hit hard with US based addresses.
Here was my finding that led to my amusement. Of the remaining IPs, the majority were US. Of the US, there were a few compromised computers at corporations (where the IT staff was here I do not know) and homes where those people obviously do not know what spam is, or know how to protect themselves.
The rest (a good majority) came from K-12 schools. I estimated about 40% of my US based blog spam came from K-12 systems across the US. Which tell me, 1) the school staff is not doing their job and 2) it is not difficult with open-source.
Scary isn’t it. So if you’re employed at a school district, beware: your schools are probably mindless zombies roaming the Internet, generating more useless junk, unless you happen to like the Casino comment spams.