No, we do not. There are already laws on the books against "dumping" their product to drive out competitors. It's called price bashing and it is illegal.
If Netflix is able to subsidize their data usage and remain profitable, great. If, on the other hand, Netflix decides to go with this to kill off the competition with the calculus that they will lose money temporarily and hike prices after the competition is gone ... well, that's illegal and on top of everything, won't even work.
Also, AT&T's ploy here won't work either. They are trying to increase data usage while hiding the cost of that usage in 3rd party fees. Yeah. Watch content providers offer two price tiers. One for AT&T and one for non-AT&T. Won't work and a waste of time. You're just shifting costs.
Also, 800-numbers became popular during a time when every street corner had a pay phone. It was about actually letting the customer contact you from anywhere, not about shifting costs.
There is no need for regulation. The market will take care of this stupidity by itself.