Powerline Internet has been around for decades. that's what x-10 has been around since 1975. Power companies have been doing this for remote reading and control of "smart meters" for a long time.
But your hypothetical example is far more problematic:
- There is no full power grid interconnect WITHIN the USA, much less between the USA and India
- Powerlines are low bandwidth for a variety of technical reasons
- Power companies filter their power signal both intentionally and simply through the process of power transformation for transmission so without active cooperation by power companies you have no ability to do this
- and this is the most important aspect:
transmission control is not the limiting factor on IoT.
IoT's biggest issue is that turning a light on in India from the USA is a solution in search of a problem. And MOST of IoT currently is EITHER
- a solution in search of a problem
- an existing mature solution wrapping itself in the banner of the latest tech fad