You can't change the laws of physics, but you can push them a long way. Intelligence today from the University of California at Berkeley, where they habitually tamper with nature as if it were a mere plaything -- I can recommend a visit to the campus, where their insouciance is illustrated by the enormous amounts of biological, chemical, nuclear and high-energy Big Science perched precisely on top of the San Andreas fault. Just in case the Big One isn't quite nasty enough, y'understand...
Anyway, today's worrying weirdness isn't very big, it's very small. Computers the size of grains of sand, with self-charging batteries, sensors and signalling gear. Scatter them everywhere for environmental monitoring, security systems, health, home control... you name it. The equations for these things seem alien to those of us used to milliwatt powers: how many picowatts of energy per bit transmitted? Using microscopic mirrors and flashing them like the Romans did heliographs, you can get down to powers so tiny that a millimetre-square battery will keep the system going for a year.
You can think of scary scenarios as easily as can I, and lots of good stuff to boot. We're going to get this, so there's no point in not thinking about it. Want a hot tip? Get into making home laboratories for fiddling with, rebuilding and reprogramming these things: they'll be everywhere, and the hackers will have a field day. So somebody's going to have to provide the soldering irons, screwdrivers and volt meters: it might as well be you.