yys

Here's one Shaw . They call it a service enhancement. There are many more either doing this already or getting ready too
A lot of isp's nowadays have the ability to see what is being sent over their networks and filter that data onto the fastlane or the slowlane so too speak. So if you are sending voice traffic over their network and it's not through their company they can limit the quality of those calls. Same thing goes for bittorrent files and such. They know what your using your bandwidth for and they can choose too slow it down or speed it up if they want.