I'm using hooks/update to control who may update particular refs in a shared repository. This works great for SSH, but I recently discovered (with git-1.6.4.2, at least) this hook does not influence WebDAV pushes, i.e., any user may update any branch.
Yes, I could add Require group ... directives as in 8 ways to share your git repository along with separate group files, but I'd like to avoid having to maintain parallel authorization configs!
Another alternative is rewriting the hooks/update, but that seems a waste given that it's already working for SSH.