the definition of "public" in public performance is not about who the broadcast goes out to, but about the relationship between the broadcaster and the broadcas

the definition of "public" in public performance is not about who the broadcast goes out to, but about the relationship between the broadcaster and the broadcastee. If I invite 100 people to my house to see a movie, it's not a public performance (supposedly) because they are coming as members of my social circle. If I instead showed at a movie theatre and charged for it, and the same 100 people showed up, then it would be a public performance because those 100 people came as members of the public. Here Aereo broadcast to customers as members of the public. Because Aereo owned the equipment, they were the ones doing the broadcasting (in the oral arguments one of the judges commented on how if instead they sold the equipment and just provided hosting, the position would be much more defensible). But, like what many others have said, the intent of the law is really what matters, and the definitions of public performance are much more about intent than about technical implementations.