[nine_k]

But once you've located the device, you can use a number of electronic warfare approaches to crack into it, not necessarily through its main radio interface. For instance, electromagnetic interference, heating, etc, all can inject a subtle hardware failure that the software is not ready to handle.

[Retr0id]

Hence, "the real advantage is surely that nobody notices you're transmitting data at all?"

[nine_k]

Not just that you are transmitting any data, but that there's some "you", or your device. "All clear, nothing to see here".