This is why I like working for a university. Firewall? Sure, you can install your own if you
want one. And we do have _some_ things walled off, but by and large most hosts are highly
exposed to the internet.
It drives vendors nuts, 'cause many of their products assume there's a draconian firewall
between them an the world, so they claim they don't need to deal with security issues. They
often know nothing about SSL, kerberos, keys,... they just trust the firewall which, to their
amazement, isn't there!
One of the best was a demo by an ERP vendor. They were showing off their stuff, how cool and
secure it was. Then somebody in the back of the room with a wireless Mac laptop took over the
presenter's session. He gave it back, but not before making his (and breaking the presenter's)
point about the system's security.