Not a security/privacy issue, but we should evaluate whether we can use this as a single patch point for removal of mozilla documentation links, and for inserting our own documentation links, etc.
@richard and @pierov Mozilla links include the locale and platform. Do we ever want to do a similar thing ourselves, or will we always be ok to just use a single href to send all users to ("about:manual" links won't need a locale anyway, but we have other support links going to torproject.org).