In a decision hailed by the American Civil Liberties Union, the Washington State Supreme Court ruled concerned parents cannot eavesdrop on their childrens’ telephone conversations.

The high court determined a mother in the town of Friday Harbor, Wash., violated the state’s Privacy Act when she listened by speakerphone to a conversation between her then-14-year-old daughter and her daughter’s boyfriend, prompting the court to reverse the boyfriend’s 2000 robbery conviction, the Seattle Times reported.

Oliver Christensen, 22, of Friday Harbor, was convicted partly based on what the mother, Carmen Dixon, heard him tell her daughter Lacey.

“The court said it is against the law to intercept or snoop on anybody’s private conversation and that even a child has privacy rights,” said Christensen’s attorney, Michael Tario. “And further, the law says it is a crime for someone to do that, and that whatever is heard cannot be mentioned in court.”

Carmen Dixon, 47, was incredulous, the Times reported.

“I just believe you have the right to know what your kids are doing and who they’re doing it with,” she said. “We were having a hard time with her as a teenager. She was sort of out of control.”

Dixon said monitoring her daughter’s phone calls was “the way I could keep track of what she was up to.”

The ACLU filed a friend-of-the-court brief arguing the primary issue was whether the use of an extension or speaker phone was considered eavesdropping.

Whether there was an exception in the case of parents and their children was a secondary issue, the ACLU insisted.

Justice Tom Chambers wrote in the court’s opinion, “The Washington act, with its all-party consent requirement, contains no such parental exception and no Washington court has ever implied such an exception. We decline to do so now.”

Attorneys for Washington state contended parents have an absolute right to monitor phone calls coming into the family home, the Times said, pointing to provisions in federal wiretap law allowing parents to tape and listen to their children’s conversations.

San Juan County Prosecuting Attorney Randall Gaylord told the Seattle paper he has not decided whether to seek a new trial, because Christensen already has served a nine-month jail term for the robbery — a purse snatching.

In the October 2000 phone conversation, Christensen told Dixon’s daughter “they’ll never find it” because he hid it “across a ditch in some stick bushes,” according to Dixon’s testimony.

Dixon said she took notes after activating the speakerphone.

Gaylord told the Times the court’s position weakens the ability of parents to monitor their children’s actions.

“I tell parents that they need to be involved in their children’s lives, and I’m concerned that this will mean parents can’t always do the right thing,” Gaylord said. “I’m concerned that a 14-year-old’s right to privacy now trumps the parent’s right to be a parent.”

Note: Read our discussion guidelines before commenting.