1) What is SOCKS and why do we not need it, and why does it block msn?

2)What is ISA for that mater

3)What if one had a proxy server, and firewall bloks all trafik not comming from the proxy server. Would this block programs that uses port 80 to try to pass the firewall.

I gues it depends if the proxy server is able to detect non http trafic.

One nasty program is the one talked about in this forum, where a client contacts a third party server through port 80, right through the firewall. And the third party server relays im & other services.