What are they gonna do if you use TOR to set up a public repo of this code? It's not like they can send their petty legal letters anywhere. If github is forced to take it down, we need some kind of a distributed github.
No, the origin is one central server. Or am I missing something? If I work on a piece of open-source code with a github repository, if github is down, nobody else will be able to access my code unless I upload it somewhere else (which doesn't happen automatically).
With git there doesn't need to be a central server. Many people/orgs use one (e.g. github) because that pattern is very well understood and most developers are used to it. There is no reason that you can't push branches/commits between individual clones (in this context called remotes). Origin is one remote, but you can set up any other clone to be a remote as well.
Just to expand on the other comments: yup, you're missing something! :D
Specifically, git is a DVCS/DSCM (distributed version control system/source code management system), which means that each "checkout" of the repository that exists is a complete clone of the original, including the full commit history and a cryptographically verifiable codebase.
In this world the "master" repository is simply a convention: everyone agrees that <insert person here> has the "master". But in reality everyone's copy is a peer of every other.
Sharing between repositories can be done any number of ways. Github is convenient, but originally email was the way code moved between copies. In fact, I host a number of my own private repositories over straight SSH.
So Github is a useful piece in the puzzle, but fortunately it's not a single point of failure in any way.
This is already the case for DRM-breaking code that is not DMCA-compliant, but you'll be hard-pressed to find a service willing to host arbitrary 3rd-party repositories via TOR.
