[madison10]

Just had one installed, may be too late to ask, but can they turn off our power remotely with one of those things? Say I have window air conditioners and they think we’re using too much energy?

[FrogMom]

That was the initial fear about them. This RF stuff came later.

[Cvengr]

Generally speaking, it is a meter, not a switch; although the meter's measurement might be read by other devices elsewhere, which might trigger a relay to open a switch.

In the above sketch, the switch controlling something like an air conditioner, would be a circuit breaker or motor control relay switch further down the circuit.

A more plausible conspiracy theory would be that the smart meter would be used with motion detection switches inside the home to identify which homes or rooms are occupied.

It has only been in the last decade that such resolution in sensing was feasible in utility systems. I doubt they are so designed in most applications.