How to prevent VI from getting a shell?

[Dan Bernstein]

In article <1990Sep18.163019.14294 at eci386.uucp> jmm at eci386.UUCP (John Macdonald) writes:
> The only
> way to prevent shell access is to patch vi to prevent it.

This just isn't true. All you have to do is break the user's !, Q, and :
keys. This turns from a joke into an easy pipe if you have pty.

---Dan