Exactly. Contracts, identification, phone numbers are not necessary for this. It could be dead simple: the application on your phone generates a pair of private

Exactly. Contracts, identification, phone numbers are not necessary for this. It could be dead simple: the application on your phone generates a pair of private and public keys. You pay some satoshis to a carrier and get some amount of Internet traffic, using your private key for authentication. If you want to switch to other carrier, you just generate a new key and send some satoshis to its account, and your modem generates a new random IMEI. You generate a new key and new IMEI for every new payment so it becomes difficult to track you and sell data about your location. And you can switch between different providers any time. You can even switch depending on who has a better signal in your current location. No need for identification, making a contract, getting a phone number, selling data about you (because carrier doesn't have it) or reporting your location to the government or courts. This is ten times better than what any provider offers today. If someone implements this, nobody will want to use old scheme anymore. Also this should promote competition between carriers.