Walls of homes are usually insulated enough to make an IR camera useless unless it's inside the home. It would be good for identifying cracks that heat can seap through though. Surveillance by laser microphones can easily be mitigated by curtains or blinds. Both of those also require the person spying to intentionally use them to spy. There is no legal commercial device that could prevent your neighbor's Xfinity Hotspot from selling what you do in your own home to Facebook/Google to use to target you with ads.