Broadcasters got the chance to officially begin their crusade to shut down TV streaming startup Aereo. Opening arguments for American Broadcasting Cos. v. Aereo and WNET v. Aereo were heard in a Manhattan US District Court today.

The group of broadcasters sued Aereo in March claiming the company's business model violates copyrights. The corporations reiterated that sentiment in court today.

"Aereo is taking the plaintiffs’ broadcast signals and reprocessing them so they can be streamed over the Internet,” said Steven Fabrizio, a lawyer for the networks. "That is a violation of copyright law."

Rather than capturing content with a single antenna, Aereo uses tiny physical antennas in its server room with each active user assigned his or her own personal antenna. Aereo says this system—having customers use a "remote TV" whose antenna just happens to be located far away—is actually a customer's right and not an infringement.

Ars previously asked James Grimmelmann, a copyright scholar at New York Law School, to evaluate Aereo's chances. Grimmelmann noted the case will likely hinge on a 2008 ruling, when a federal appeals court ruled that Cablevision did not infringe copyright after it created a "remote DVR" system (in which the physical DVR hardware was located in a Cablevision server room rather than the customer's living room). Cablevision succeeded for two reasons: users were ultimately in charge of what programs were recorded then played back, and Cablevision stored a separate copy for each user who viewed a program than rather creating one copy for streaming. It remains to be seen if Aereo can create a similar defense.

Broadcasters presented one additional claim outside of the infringement of Aereo's business model. The companies claim Aereo is illegally engaging in public performance because it transmits programs live. Such public performance requires a license under copyright laws; Aereo rejects this idea as well.