The technology to convert wifi signals into the placement and identity of people is getting much better. Not by using their devices, just the waves bouncing of their bodies. (There’s nothing new to the pipeline as far as I can tell, we’re just starting to get into the accuracy ranges that make it easy/useful.)
They could do the same thing with a speaker playing a sound. It’s basically sonar, but the waves being measured are RF and not sound. But it being outside your home wouldn’t work that well; wifi does not penetrate wood or plaster walls very well, and won’t get through brick or metal at all. They can shape it, to go around things, but unless it’s extremely high powered, it won’t go through anything solid.
Similarly for a whole bunch of attack vectors. Reconstructing keystrokes from keyboard sounds has been demonstrated. But you need a quiet background and a close microphone. At which point you probably could have just plugged in an inconspicuous keylogger and be done with it.