Years ago, I used as a nickname in the internet the name of a puppet in a german childrens television show, Käpt'n Blaubär (literally Captain Bluebear). I also used this to sign up for my free email-account. The company providing the account required a real name and address during registration, so I had to give them my real address next to the fake name.

A couple days after registration, I got their letter with the necessary confirmation codes to activate my account. On the envelope, the postman had written: "WDR? Köln?" which is the address of the TV company of the show. They nonetheless delivered the letter to me. And I am certain it took the postman sometime to write it down and decide what to do with it.

The company, by the way, never checked the name until, several years later, I had to contact their support. Instead of answering my quiestions, they had me to give them my real name.