That rule needs to change IMO. It seems rare anymore that there is a punt, kick, or interception return when this penalty is not called.Too often the "block" has little if anything to do with the end result. It seems to me that if one is detected, but doesn't affect the play, the flag should be picked up or at least a very minimal penalty should be imposed unless the block was malicious. The penalty is ruining punt and kickoff returns.