git push controls / config

From: Mahesh Vaidya <forvaidya@gmail.com>
Date: Jun 22, 2010, 10:50 UTC
Message-ID: <AANLkTin8O01vNL8JlPcNqB7FdvMssjOce_YFF82iW6GC@mail.gmail.com>

How can I prevent (via a config file) someone from pushing a

1) same commit with --amend;
      - we rely on commit log; bug number. If some one changes bug
number via amend; that risks the integrity.

2) creating and removing Tags and Branches
    - same - Tags are of special importance to us.

Thx/ Mahesh