[mrsuprawsm]

They do have a "committed by" feature that appears when you cherry-pick someone else's commit to a branch.

It shows up as "Bob committed with Alice".

I've only noticed it showing up for cherry-picks, I'm unsure if that's the only place it's used.

[terinjokes]

They show that if the git commit has differing author and committed fields (It shows up when I reorder and squash commits on branches before merging).

All one has to do to make it go away is change the committer field on the git, this isn't security added by GitHub.