The US department of Justice (DOJ) on Monday came out in support of TV networks in their upcoming Supreme Court battle against Internet TV startup Aereo. In a brief filed with Court on March 3rd, the DOJ said that Aereo is "clearly infringing" on the copyrights of TV broadcasters by picking up their free, over-the-air TV signals, and retransmitting them to consumers via the Internet.

Aereo "transmits copyrighted broadcast programs to the public, without the authorization of the copyright holders, and is therefore liable for infringement," the DOJ said in its brief.

At its core, the question is whether Aereo streams the content over the Internet, or does it only provide customers access to equipment needed to stream the content. While Aereo says its service is a private performance, as each user is assigned to a tiny remote antenna, TV networks argue otherwise.

Although the DOJ agrees that Aereo uses individual antennas to receive the signal, it's the use of centralized servers and other equipment that doesn't make it an individualized end-to-end system. While the DOJ's brief is just a piece of advice, which the court is free to ignore, its show of support for TV networks is definitely a major setback for Aereo in its Supreme Court battle.

The company, which just announced its Austin launch, said that if it "is not allowed to continue, neither are network DVRs, which would be a huge step backwards for a lot of these industries". On the other hand, broadcasters like CBS and Fox have threatened to cease broadcast, should the Supreme Court decide in Aereo's favor.

After federal courts in New York and Boston last year sided with Aereo, an Utah federal court last month sided with broadcasters, and imposed a preliminary injunction on the company's operations.