The only example, which is kind of spurious, that comes to mind is drought in Texas - if you're watering your lawn during a drought, or decide to fill up your empty pool, I believe that there are actual legal consequences.
True, though I believe that in most jurisdictions that's just a normal law, done separately from the utility company. In states where rules about watering during a drought are legally enforceable, if you're caught watering your lawn when you aren't allowed to, you get issued a ticket/fine from the local police, not from the water company.
Bandwidth certainly is a scarce resource as is the equipment needed to support it. Fiber doesn't just magically appear in the ground. Switches don't grow on your street corner. These things have to be paid for and maintained. It only makes sense that the highest users pay for more for the infrastructure. It's the current pricing schemes that I have a problem with.
That's the throughput, though (which was always capped, in Mbps) not the amount of data. The latter is unlimited.
They're limiting the amount of data not because it's scarce, but because that forces people to limit their throughput - since if you use at the max levels, it'd reach the data caps in no time - because they're overselling too much and don't want to pay for the infrastructure upgrade.