On Wed, Jul 18, 2001 at 11:14:35AM -0400, Dan wrote:
> (sorry for spamming the list if every Debian user but me knows about this) 
> 
>     $ apt-get moo
> 
> Just try it!

...using a testing or unstable apt-get.  The stable version just says:

# apt-get moo
E: Invalid operation moo