The lawsuit claimed that Viacom secretly kept track of children under the age of 13 who streamed videos and played video games on its Nick.com website, and shared what it learned with Google.
It said both companies then without permission put text files known as "cookies" into the children's computers, letting them gather additional information that advertisers could use.
The lawsuit was brought on behalf of young children who registered to use Nick.com.
But in a Jan. 20 decision, U.S. District Judge Stanley Chesler in Newark, New Jersey found no showing that Google and Viacom could identify which children streamed specific videos or played specific video games, as opposed to identifying children generally.
He also found no showing that the companies engaged in "highly offensive" behavior for which they could be held liable.
"Children do indeed warrant special attention and heightened protections under our laws and social norms," Chesler wrote.
"Although plaintiffs have identified conduct that may be worthy of further legislative and executive attention, they have not cited any existing and applicable legal authority" to support their claims, he added.
The plaintiffs had accused Viacom of violating the federal Video Privacy Protection Act, and both companies of violating a New Jersey anti-computer hacking law.
Chesler dismissed other claims last July, and said the plaintiffs cannot amend their lawsuit again. The litigation against Mountain View, California-based Google and New York-based Viacom began in 2012.
Evan Rosenberg, a lawyer for the children, did not respond on Wednesday to requests for comment.
A Nickelodeon spokesman said the Viacom unit is pleased with the dismissal. A Google spokesman declined to comment.
The case is In re: Nickelodeon Consumer Privacy Litigation, U.S. District Court, District of New Jersey, No. MDL-2443.
© Thomson Reuters 2015
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