When your validation logic is too aggressive. Tony Hawk gets deleted because "that can't be the real Tony Hawk" and Dallas Tester gets nuked because an airline's regex thinks he's a test account. Classic case of overzealous input sanitization that treats legitimate edge cases as security threats. This is why we can't have nice names in production.
Somewhere, a developer is adding if(name != "Tony Hawk" && !name.includes("test"))
to their validation code and calling it a day.