Oh, its real rare. Think about it like this, though. Most people who get electrical damage are not from huge voltage spikes like a direct hit from a storm, but from small and constant spikes hitting the computer that after awhile will start to render damage and then eventually you get hardware failure. Most people think this to be a one time voltage spike, and actually its just small spikes overtime causing damage. On rare cases a direct hit will jump any surge protection (even heavy duty house). Usually its a HUGE surge, blows the house fuse, burns the wiring, will still be powerful enough to blow any little fuse connected to a surge strip, blow it and blow ruin the computer. Anyhow, the best protection is really to just unplug the thing. Like I said, its possible but the real danger is prolonged exposure to small spikes. So, unplug it for the big ones, and for the small spikes use a line conditioner.