This is shocking to hear, but I guess if it threatens the bottom line, you can’t get away with it. Nike reportedly isn’t happy about its NFL endorsers wearing custom sneakers that cover up their branding.
Nike reps sent out a pamphlet to players warning that “NIKE views third-party customization (or post-embellishment) of Nike footwear to be a violation of the Contract, triggering NIKE’s right to immediately terminate the Contract”.