I found a very powerful expired tumblr blog. But when I tried to register the name, tumblr tells that the name is already used (`Try something else, that one is spoken for.`). What can cause this? If someone else registered it before me, can it still return 404 code? How do I check that it is expired: 1. When I visit the blog, I get the following message: There's nothing here. Whatever you were looking for doesn't currently exist at this address. Unless you were looking for this error page, in which case: Congrats! You totally found it. 2. I checked HTTP return code and it is 404.