Review Suggested Edit

GitHub has a setting wherein they offer to "anonymize" your user email from, say, somebody@example.com to somebody@users.noreply.github.com. I presume this is to prevent you from getting spam from a scraper that reads the metadata on commits to public repositories.

How do they do this without invalidating the commit? Isn't the commit message, user, timestamp, and so on hashed along with the worktree state to get the commit hash?

My local Git is happy to pull stuff that other people have written on top of my commits with the anonymous author.

Does that mean that _anyone_ with a clone of the repository can rewrite authorship of all the commits and still maintain the commit hashes of the original? Or is GitHub doing some giant translation between commit hashes on different forks?