I've felt that uncomfortable tingling and occasional shocks on a number of laptops, be they metal chassis (Macbook) or plastic. Some friends report being zappe

I've felt that uncomfortable tingling and occasional shocks on a number of laptops, be they metal chassis (Macbook) or plastic. Some friends report being zapped by their Macbooks. The weirdest for me was my first laptop. I kept getting shocks from the palm rest, even though it was all plastic and presumably a good insulator. I didn't understand how a shock could reach me through solid plastic.