I've had the domain zbz5.net for some years now, even though it's been just a holding page for most of the time before I started this blog. Occasionally I've been using it for testing purposes though, and this is the source of my agony.
I was testing out HelpBurner and its capability to post directly to Drupal. I did not get it to work, and in the process of finding out why, I opened up the Blog API module for anonymous users (just a test site, remember..)
But I still did not get it to work until I got some help from @helpburner via twitter
And this is when I make my stupid blunder: I forget to disable the Blog API. I forgot about the test site in its entirety until a colleague of mine pokes me, and asks if I've started doing dubious stuff after hours. My site was filled with SEO spam, more than 4000 entries of incomprehensible collection of dubious words.
The result is that this is my top ten search terms on google analytics:
Lesson to learn: always clean up your test sites!