Beamforming around moving (or even static) obstacles? Integrated motion sensing with fewer false positives for smart bulbs, doorbells, whatever? Or more realistically, your TV can make sure you don't skip the commercials. I probably wouldn't use that stuff myself either, but it's interesting to think about.

Why would I care that my neighbor knows we're home and moving around? If they really wanna creep on us, they can already use IR cameras or audio amplification or laser mics or whatever.