alt Hacker NewsLaffer curve is about percentages (and also irrelevant below 80-90% and irrelevant if you think government shouldn't be a business). Taxing people with zero money millions of dollars isn't even on the curve, it's just a completely separate bad thing.
The separate internet tax on the other hand, that's about 1000% of the cost of internet, and a 1000% tax is definitely on the wrong side of the laffer curve. They are essentially banning the internet.
The laffer curve is the law of diminishing returns applied to taxation revenues. It is relevant anywhere the government cares about tax revenues rather than being punitive or arbitrary, and its effects depend on the item being taxed and the effect this has on the wider economy.