Firewall and user services that needs open ports

[Bruno Wolff III]

On Sun, Jun 22, 2008 at 16:53:10 -0400,
  Chuck Anderson <cra at WPI.EDU> wrote:
> 
> Why do we need a firewall when you can easily prevent services from 
> being accessed...just stop the service!  Don't bind to the port, and 
> it won't be possible to connect to it.

Because there are network services that you only want accessible locally.