For me this has been the case for the power supplies. First one (came with the original intel macbook pro) actually caught fire due to a short caused by a brea

For me this has been the case for the power supplies. First one (came with the original intel macbook pro) actually caught fire due to a short caused by a break in the wires at the base of the brick. A power supply bought last year is starting to split near the magsafe connector.