For many a reason people will use open source applications on their expensive MS Windows, which in some cases came with the machine at sale time, as they find most large MS Windows based application too expensive.
Since our local incumbant ISP karoo started offering an "up to 8mb" service they have been throttling traffic. For most people using this ISP this throttling of traffic will not matter but for others who use the most throttled protocols, like P2P and Usenet, we will feel the slowdown.
The ISP calls it "Traffic management" but in reality it is a traffic shaper. They throttle because they refuse to invest in more bandwidth. It really is as simple as that.
Now, going back to myself using P2P to download. I have seen what was once a guaranteed 100% speed with hundreds of seeders drop to 60% less and still there are hundreds of seeders.
I personally find this an abuse of purchase. The thing is though we cannot go elsewhere as they are the only ISP in town who does ADSL.
I am annoyed. Are you? If you are then let them know. I doubt they will ever invest to such a stage as they no longer us traffic shaping but at least you will have told them you are annoyed.