You are trying to solve a social and legal problem with technology.

We all know if Wikileaks wanted to open a new handle, there's really nothing Twitter can do to preemptively stop them. They can only react with a game of whack-a-mole.

And that's what they do. Avoiding a ban by creating a new account is already against the terms of service.

Imagine an unauthorized client that overlays on top of vanilla Twitter. Instead of subscribing to Twitter handles, you subscribe to cryptographic identities. Participating Twitter publishers cryptographically sign their tweets, proving their identity. The overlay client regularly scans the entire site's feed to discover any new handles using a known signature. If Twitter Inc. bans your handle, just fire-up one of your sock-puppets and all your overlay subscribers seamlessly re-point to the new handle.

So then Twitter (or a motivated investigator) runs the overlay network as well and gets the new account automatically identified.