Here's a history lesson for you … Sealand and HavenCo, the "secure offshore datacentre". It's alleged to be dead – by the main admin, who now runs a competing service in the US.
Start with the Wikipedia Sealand article, then hop over to the Defcon-11 presentation held at Metacolo (or the more readable googleised html version
Some ISPs seem to have started to send warning emails to people running their own DNS servers badly … specifically to address the currently publicised “Open DNS server” security problem.
If you run your own zones, check them out with the handy www.dnsreport.com website. Don't just automatically follow their advice – even google's zones get warnings. I expect that google know what they're doing :-)