twitter.co.uk
Have you ever typed twitter.co.uk into your browser instead of twitter.com? If so, you may have been surprised to find yourself on a completely different site, rather than being transparently redirected to the one you thought you were going to. The reason for this is that the domain is not owned by the Twitter company, but an individual named Steve Crawford, who is currently inundated by emails from the site as people enter something@twitter.co.uk as their email address and then start being ‘followed’ by other users—causing Twitter to send a new email each time.
This is partly Twitter’s fault, as they do not make any attempt to verify the email address you supply when registering. Not only does this hammer the wrong user/mail server with emails if an incorrect address is provided, but it also means that the real account owner cannot reset their password either. On the other hand, I have slightly less sympathy for Steve as he must have switched on a catchall address if he is actually receiving all these emails, which is asking for trouble under any circumstances from spammers who email all common names and words at every domain they can find. Of course, turning off catchall would still hammer his mail server and be rather annoying, but at least the emails would be rejected.
One does wonder why the people behind Twitter didn’t register the name with other extensions—the UK in particular is a big online market and .co.uk is probably one of the most common country domains, possibly because it doesn’t impose any residential restrictions on registrants. However, they haven’t figured out how to make money from the site yet, and openly admit to holding off implementing such features, so I don’t expect them to be clued-up on the topic of registering domain names under different suffixes.