its technicalli impossible for the isp to determine the throughput of for instance kazaa for all their costumers...

--Actually it's not impossible for ISPs to determine how much bandwidth a user is extracting through Kazaa or other networks-- That s not true. Some months ago the Deutsche Telekom has written letters to their users that they have to stop using filesharing programms. And if they can notice that u use the programms, they can also log the traffic.

Well i havent been on kazzaa for awhile but i see it is now time to add to my 2000+ songs thank you warp 2 search for the "good looking out" lol

What if multiplayer game (insert game here) and instant messenger (insert IM brand here) and a linux app of some sort share the same ports that kazaa uses and the person getting hammered with charges doesn't even use Kazaa?