I had one illegal club chip that I shipped returned to me in that condition. To avoid having the post office cancelling machines "eat" the chips I was sending out, I requested that they be hand cancelled. After I got the broken chip back I remembered watching the postal worker slam the hand cancelling stamper onto my envelope. This action obviously broke the chip that was inside. I now request that they apply a meter strip to each envelope. The meter stripped letters are placed in a bag and are never seen by any machines. I have not had a problem since.