Your friend may not understand it, but there is a reason that kazaa is banned on most networks. On a normal network, most users might browse the web sporadically causing short bursts of traffic over a second or so that only use up a fraction of the bandwidth. Kazaa, on the other hand, is going to use the maximum upload/download available if you let it. Rather than fitting hundreds, maybe even 1000 users on your internet connection, you can fit ONE user. The other people are probably going to start failing to pull up web pages (20-50% time out).

I used to maintain a network in my fraternity house. We had 20 people sharing one ADSL line (1554/256 kbps). I had a heck of a time convincing people that Kazaa, etc. would seriously hurt the other users on the connection. People would get seriously pissed at me when I would cut off their connection. Then, the next day, they would get pissed when they couldn't even read their email because somebody else was using Kazaa.

Still, I managed to keep things largely under control without burning any bridges. Since I moved out, the network works only sporadically. They want me to upgrade the network with a router that has more advanced functionality (time-based filters, packet shaping, etc). I haven't figured out what to get yet, but I think it is kind of funny.

My point is, you can seriously harm the corporate network your friend is on and prevent his coworkers from being able to get their work done. More to the point for your friend, if it works successfully, he WILL be noticed and action will be taken.

Just my 2 cents,

-Biscuits