If the rest of the internet is presumed to be linkable with a specific identity, I challenge someone to figure out who represents http://www.banksy.co.uk/. And Pest Control doesn't count. And if it does, then that's a pretty easy way to hide your identity.
This is a good question. Most of the comments here seem to be concerned with figuring out voidnull's identity, rather than the motivating idea of whether such a thing is possible.
The easy answer to your question is, Banksy represents that domain. But perhaps he's not so easy to pin down? Still, I'd think the crew involved in Exit Through the Gift Shop[1] might have some leads. Seems solvable, that is.
