This bears highlighting. The water company, regulated as a public utility, will fine people for using "too much" water when they decree they are running out. And water usage is a lot easier to model than broadband. Do you want that same mentality running the broadband companies?
Your question is about metered versus "unlimited, but not really" billing. With "unlimited, but not really" billing, you get throttled or cut off, but under a metered billing scheme heavy end-users pay more for the traffic generated as a result of their requests.
This bears highlighting. The water company, regulated as a public utility, will fine people for using "too much" water when they decree they are running out. And water usage is a lot easier to model than broadband. Do you want that same mentality running the broadband companies?