VIDEO-Supreme Court reverses lower court on Aereo, says Aereo violated copyright law

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Aereo CEO Chet Kanojia leaves the U.S. Supreme Court after oral arguments April 22, 2014 in Washington, DC.

On a 6-3 vote, the court handed a victory to the four major TV broadcasters and cast Aereo's immediate future into doubt.

Backed by media mogul Barry Diller, the TV-over-the-Internet start-up, was launched in 2011.

Last week, Aereo founder and CEO Chet Kanojia told CNBC his company charges for technology not TV content, and therefore is not infringing on copyrights.

Any customer can buy an antenna and DVR for their home and watch and record their local channels, said Kanojia—adding that his company is doing the same thing but with more modern technology.

The networks including CNBC's parent NBC as well as ABC, CBS, and Fox said Aereo steals free, over-the-air programming and then transmits that content to its online customers, without paying retransmission fees to the broadcasters.

—By CNBC.com. Reuters contributed to this report.

Disclosure: CNBC's parent company, NBCUniversal, is among the broadcasting and cable companies opposing Aereo on copyright claims before the Supreme Court.