I grew up with CDs and never knew of one cracking. With sufficient scratching it was possibly to get them the skip, but even friends who kept CDs unboxed in piles round the CD player didn't have this problem.
No, but if you manage to scratch the aluminum foil layer on the backside, the CD instantly becomes useless. Or when you store cd's in large unboxed stacks, they can stick together, which can also damage the backside.
It seemed to me the main risk was those CD cases with the little plastic fingers on the centre; they seemed to require a big force to get the CD in or out.
I grew up with CDs and never knew of one cracking. With sufficient scratching it was possibly to get them the skip, but even friends who kept CDs unboxed in piles round the CD player didn't have this problem.