Aereo Inc. sells a service that allows its paying subscribers to watch television programs over the Internet at about the same time as the programs are broadcast over the air. Most of these programs are copyrighted works. Aereo neither owns the copyrights in those works nor holds a relevant license from the copyright owners.

When an Aereo subscriber wants to watch a show that is currently airing, he selects the show from a menu on Aereo’s website. Aereo’s system, which consists of thousands of dime-sized antennas and other equipment housed in a centralized warehouse, responds roughly as follows: A server tunes an antenna to the broadcast carrying the selected show. Each antenna is dedicated to the use of a single subscriber. A transcoder translates the signals received by the antenna into data that can be transmitted over the Internet. A server saves the data in a subscriber-specific folder on Aereo’s hard drive and, once several seconds of programming have been saved, begins streaming the show to the subscriber’s screen (personal computer, tablet, smartphone, Internet-connected television, or other Internet-connected device). The streaming continues, a few seconds behind the over-the-air broadcast, until the subscriber has received the entire show. The data that Aereo’s system streams to each subscriber are the data from that subscriber’s own personal copy, made from the broadcast signals received by the particular antenna allotted to him. Aereo’s system does not transmit data saved in one subscriber’s folder to any other subscriber. When two subscribers wish to watch the same program, Aereo’s system activates two separate antennas and saves two separate copies of the program in two separate folders. It then streams the show to the subscribers through two separate transmissions—each from the subscriber’s personal copy. 

Various television producers, marketers, distributors, and broadcasters that own the copyrights in programs that Aereo streams sued Aereo for copyright infringement. They sought a preliminary injunction, arguing that Aereo was infringing their right to perform their copyrighted works publicly. A federal district court denied the preliminary injunction, and the U.S. Court of Appeals for the Second Circuit affirmed. The U.S. Supreme Court granted the copyright owners’ petition for a writ of certiorari. How did the Supreme Court rule? Did Aereo’s actions amount to performances of the copyrighted works?