Don't forget that domain names are intellectual property and as such are vulnerable to information security issues. Google temporarily lost control of google.de earlier this week when someone, somehow, managed to get the DNS entries transferred from Google's ISP to another.
A spike in the incidence of domain hijacks made headlines three or so years ago but the numbers fell when ISPs and registrars improved the registration and transfer process controls. It is quite difficult now even for the legitimate domain owner to transfer it - one of the typical hidden costs of security.
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