Why do you think they don't have a license from Entropic in the contract they both agreed to? Unless they are utterly incompetent, their contract with Entropic covered this and if Enrtopic delivered firmware that they don't have rights to, that's on them, not on Def Con. Anything that comes to Def Con just results in a lawsuit against Entropic. Additionally, he apparently wrote the code on the plane prior to his arrival and then worked to get it on all the badges. That's going to make it pretty hard to argue that they don't have permission to distribute the badges with this code on them.