The U.S. Supreme Court threw out Google’s appeal to review and dismiss a class-action lawsuit that alleged it violated the state’s Wiretap Act when it secretly collected personal data from unencrypted private Wi-Fi routers while on the verge of boosting its Street View service through camera-equipped cars roaming around neighborhoods.

The federal Wiretap Act prohibits the unauthorized access or interception of electronic and wire communications to protect the privacy of its citizens.

“We’re disappointed that the Supreme Court has declined to hear the case,” says a spokeswoman of Google.

Research reveals that San Francisco District Judge James Ware approved in June 2011 some combined private lawsuits from complainants who wanted to sue Google for Wiretap Act issues. The company agreed to settle the probe in March 2013, involving the District of Columbia and 38 states in the U.S. by paying $7 million and with the agreement that it would destroy the collected data. Then in September 2013, the 9th U.S. Circuit Court of Appeals denied exempting Google from such liability.

Google admitted its Street View cars sucked personal data from the unprotected networks in residences form 2008 to 2010, while the car collected location information and photos for its maps service. The interception was able to gather user names, emails, passwords, web-surfing history and payload data among others.

The company earlier argued in court that data interception from unprotected Wi-Fi connections, which it considered a form of radio communications, is legal and not governed by the wiretapping law.

“The Wiretap Act, 18 U.S.C. §§ 2510 et seq., permits interception of 'radio communications' that are not 'scrambled or encrypted,'" reads [pdf] Google’s court document.

The high court, however, dismissed the concept and explained that radio and Wi-Fi are two different things.

“The court reasoned that 'radio communication' encompasses only 'traditional radio services,' and not other technologies that also transmit data using radio waves, such as cellular phones and Wi-Fi networks,” writes the court document.

The plaintiffs were grateful with the court’s decision, describing it as an important victory for users of Internet service.

“The Supreme Court left in place a decision that protects private residential networks from snooping by Google and others,” shares Marc Rotenberg, who is one of the plaintiffs and from the Electronic Privacy Information Center.

Based on other reports, some countries are also conducting investigations on the Street View case.