What type of surveilance can see and hear everything you do, wherever you are, without having to be near you (i.e. with a van,e.t.c.)?

I don’t expect to find an answer here but maybe I’ll get lucky. Thing is, I know this type of technology exists and am intrigued by it, yet I do not know of the technical details (i.e. is it radar, thermal imaging, some sort of sattellite technology, e.t.c.). What I am envisioning is like “big brother watching you,” a veritable panopticon, where nothing goes undetected by some unknown and secret eye. This technology can go through walls, so not mere camera imagery. It can derive highly sensitive visual and audio data, and perhaps software can remodel images (i.e. to make a thermal image look more lifelike and be able to discern minute details such as facial expressions and line of sight). I am guessing this is something not publically disclosed but no doubt used by government agencies and most likely the private sector (i.e. ex-F.B.I. perhaps). Let’s just say I have MORE than a hunch this type of technology exists, and assuming it does, will threaten the privacy of EVERY individual in the future when it falls into the wrong hands. But I digress. I just want to know what exactly it is so I can satisfy my curiosity. If you know of this please be as specific as possible in your details. If this sounds like sci-fi to you, I assure you it is not.