Why NBA is Banning "Ninja Style Headbands"? For the upcoming season, the NBA intends to introduce some changes to the headband options. Teams as well as players were notified with a memo issued by the league about the discontinuation of “ninja style headwear” going ahead. In an official statement by Mike Bass, NBA spokesman, the headwear has failed to satisfy the league approval process. Teams have also expressed their concern in terms of safety and consistency of size and length of the headband.