Wouldn't the companies then compete viciously?
Here in the US, telecoms are treated as utilities, like power or water service.
You don't want each power company or water company, digging their own trenches in every street. They access common utility lines and share the administration of them, having access to the particular market those lines service.
Since telecoms also have to trench (and destroy city streets) to expand into new markets, they are also regulated as utilities and have access to one another's infrastructure for reasons of preserving competition.
However, they are NOT allowed to jack their rates when only 1 telecom is able to service a particular area.
Nor are they allowed to deliberately sabotage their lines so that only 1 telecom provider can function on them.
Implementing bandwidth caps or otherwise discriminating against netflix/hulu users is a mechanism of artificially manufacturing competition since they are losing business on their cable television service.
It's not just Roku users like me that will be affected, either. It's a direct strike against DirecTV and their OnDemand feature. With DirecTV, you can either watch live via Satellite, DVR via Satellite and watch later, or download to your DVR via OnDemand much like a Roku or BitTorrent style of viewing.
Residential telecoms have lost the hardline phone, and are starting to lose the hardline cable TV connection. All they have left is ISP service. This attempt to jack the cost of ISP service is the wrong way to go. They're preserving their buggy-whip plants (phone and cable TV infrastructure and staff) by subsidizing them with ISP rate hikes, rather than winding down those services.
Go lean, or go out of business.
ETA:
I'd also argue, that Cox (or other ISP) users that commit to a data package that says 8mbps/20mbps/50mbps or whatever rate they choose, should be ABLE to download at that rate, any time they want to do so. I pay for the 50mbps rate. Because I consume Netflix/Hulu stuff and also because I telecommute from home. If I'm at home and watching something in the evening on Netflix, and there's a slowdown in video quality because some cheapazz *expletive deleted*hole next door with the 8mbps plan also starts Netflix (or downloads a DVD ISO file, or whatever)... or even if my neighbor has a plan on par with mine... I should still be able to download at 50mbps. No matter the total neighborhood consumed bandwidth, if I pay for 50mbps, then I should get 50mbps.
If that ain't the case, then offer a low packet-priority plan with a 5mbps plan for all the cheap people to buy, and a high packet-priority 50mbps for the people like me to buy.
But be HONEST about it.
I pay for 50mbps, any dang time I want it, all month.
Don't try and short me on that. Bastages.