Yeah, they do. Big V8s usually require premium gas.

Premium gas costs more. Race cars need race gas — that costs even more.

Does the gas station check what car is pulling up, or do you choose based on what you think works best for the engine?

Depends on the business model. A New Jersey gas station will deny you the freedom of putting diesel in your Civic.

I agree with you that it's a bad analogy. But to be fair, all-you-can-eat buffets are not really all-you-can-eat, and will kick you out if you try to consume more than what they calculated a regular consumer does. All service providers do this when they falsely advertise "unlimited" anything.

Where ISPs cross the line is by trying to also enforce _how_ I can consume the data I'm paying for. Having plans that restrict tethering is consumer-hostile, plain and simple. Whether I'm tethering or not has no relation to how much data I consume. They can continue to restrict bandwidth and data limits if I go overboard, but I'll be damned if I allow them to tell me how I can use it.

So if we're going with the buffet analogy, then it's like them saying I can only use a fork to eat, as someone mentioned above.