My concern is mostly related to the various IC components such as CPU. I know that one of the problems of miniaturization is that electons jump to neighbouring lanes. Given how tight things are in an IC, a magnet would excite and strengthen the "jump" behaviour of the electrons.
How strong a magnet has to be to affect a CPU or other modern electronics components found in modern cell phones? Is a casual car magnetic holder strong enough to stress the hardware (given it's attached directly to the casing - too close)