Why not just increase sales tax? Or make sales tax sector by sector. Since they are almost a monopoly, it will come out of their own pocket mostly.
They would have to lower their prices in order to keep the same price to the end user (to keep the same number of users) and therefore get less profit.
Is it because in the states you show the same price and local (state) sales taxes are added on top that makes it a tax to the consumer?
Could try and pass legislation to force all companies to only ever advertise after-tax prices, but that's a doozy to enforce.
Sales tax is always regressive. The only ones who are paying it is the consumer.
We have no problem enforcing the after-tax rule in VAT jurisdictions.