I don't race, and don't plan to apply this practically, but I've been hearing about Shimano's electronic shifting, and have been idly wondering this: Since the wires aren't shielded, would it be possible to jam the shifter system with powerful enough electromagnetic interference from, say, a car parked at the edge of the road? Would this be possible but improbable, impossible altogether, or relatively feasible?
Probably nearly impossible. If you induce a large enough current in a few feet of cable to mess up the shifter, you'll be inducing the same amount of current along anything that conducts. It'd probably be enough to cause physiological effects in the riders (causing muscles to contract). You're talking a huge amount of power to induce that much current from feet away, like hundreds of amps into a coil the size of a car.