Digital rights advocates, the American Cable Association, Dish Networks and a coalition of law professors are among a broad array of outside groups that are asking the Supreme Court to side with Aereo in its battle against television broadcasters. They argue in various friend-of-the-court briefs filed on Wednesday that the Second Circuit Court of Appeals correctly rejected broadcasters' request to shut down Aereo, a startup that allows paying subscribers to stream over-the-air television to phones, tablets and other devices. The Barry Diller-backed Aereo also offers DVR functionality that allows people to “record” shows for later viewing. The Supreme Court will hear arguments about Aereo's legality on April 22 and is expected to issue a decision by June. Television broadcasters that are suing Aereo contend that the company infringes copyright by “publicly” performing shows without a license. Aereo counters that its streams are “private” performances, due to the company's architecture, which relies on thousands of tiny antennas to capture over-the-air transmissions and stream then on an antenna-to-subscriber basis. The groups that filed friend-of-the-court briefs this week offer an assortment of different arguments against the broadcasters. The American Cable Association says in its papers that Aereo's technology merely provides another means for consumers to access and record over-the-air tv -- as they are legally entitled to do. Aereo “serves the public's right to tune in to signals broadcast over the public's airwaves and to do, remotely, what has long been permissible using the functional equivalent of home-based equipment,” the organization says. Digital rights advocates, including Public Knowledge and the Electronic Frontier Foundation, take issue with the argument -- advanced by Aereo's critics -- that the company's tiny-antenna system is a “sham,” designed solely to take advantage of a loophole in copyright law. “The supposed inefficiency of Aereo’s multiple-antenna system as compared to cable systems has no bearing on whether Aereo’s technology enables private or public performances,” the digital rights groups write. “Attempting to distinguish 'legitimate' from 'sham' innovation would place the Court in the role of technology regulator, attempting to decide the worth of a given technology.” The groups add that many technologies can be valuable even if with seemingly inefficient features. “Aereo’s technology has the potential to bring new viewers to broadcast TV, increasing advertising revenues and allowing broadcast programming to better compete against cable programming,” they argue. The law professors say in their brief that Aereo's system is the “functional equivalent” of the Sony Betamax -- which was allowed by the Supreme Court decades ago. “Consumers use [Aereo] to record television programs for subsequent playback to themselves. In copyright terms, these are reproductions subject to the Copyright Act, many of which are likely protected as fair uses,” a group of 36 law professors argue. Last month, the White House weighed in against Aereo, arguing that the company infringes copyright by retransmitting programs without licenses. The Department of Justice says that Aereo's streams are “public” performances, because Aereo transmits the same program to numerous people.