> There are a number of things that are easy to block, such as web
> traffic, smtp traffic, web traffic to a particular IP address or
> network, most IRC servers and so on. There are a number of things
> are much harder to block, such as MSN Messenger, Kazaa, Yahoo!
> Messenger, and so on.
I'm not an expert in this area, but...
Wouldn't MSN Messenger and YIM etc. connect with one (or a limited
number of) server(s), which could then be blocked using some
Kazaa clients would be a problem, but again the server should be
block'able in much the same way.
... Or am I missing something?