This is pretty frightening all by itself, but I'm thinking: if this is possible with a router, should't a simple smartphone be capable of the same, since it can be used as hot-spot, and covers even more signal ranges? A device owned by everyone, everywhere, generally less secure and more carelessly used, with loads of proprietary software pretty much always installed? Does it mean the whole city can be almost realistically observable by someone, even when no video camera is there?