If, as you say, you accidently check in a file that contains your CC numbers,
you can use the "Shun" mechanism to remove that file from the repository, and
to prevent it from being added again in the future (for example due to a
sync.)

The Shun mechanism was created for this and related purposes:  to remove
wiki-spam or inappropriate or obscene comments or remarks or to remove
copyrighted material or material that contains trade secrets.

Shunning can be done from the web UI.  For some screens that show a single
artifact, there is a "Shun" submenu option.  (You have to have Admin privilege
to see it, I think.)  Or you can type in the SHA1 id of an artifact in the
Shun screen which is found off of the main Admin page.  Shunning takes effect
the next time the repository is rebuilt.