s4w3d0ff/cryptographicanomaly — pull request #1 by tf2honeybadger (2014-02-09 22:54:28+00:00)
Title: Kill the forking monster of doom!

Included are changes that will cut off the evil forking monster from the CGA network (will automatically wipe and redownload everyone's blockchain, version change to make new clients reject old clients), and a new checkpoint.

I think this describes it fairly well:
(04:49:26 PM) tf2honeybadger: this is like a midair refueling, but the fuel ports are epoxied shut and one of the planes is actually a car with wings and propellers