Helicopter parenting is reaching ever-loftier heights, thanks to GPS-connected gadgets that allow parents to track their child's every movement. But putting a tracker on your kid could be a bad idea for reasons besides the psychological, consumer advocacy groups claim.

Some smart watches aimed at kids, in particular, are susceptible to being hacked, allowing strangers to track children and even communicate with them without parents' knowledge. That's according to a report from the Norwegian Consumer Council, which commissioned extensive testing on four models of GPS kids watches.

US consumer groups are now warning parents not to buy the devices, and they're asking the government to investigate if the devices run afoul of laws concerning privacy and consumer protection.

"You have a watch that's being marketed as keeping children safe and a way for people to keep tabs on their children, [but] that's actually putting children at risk," said Josh Golin, executive director of the Campaign for a Commercial-Free Childhood. His organization, along with the Electronic Privacy Information Center, the Consumers Federation of America, Public Citizen and other groups, laid out their concerns in a letter to the Federal Trade Commission (FTC) Wednesday.

Kids' smart watches, while a relatively niche item, appeal to busy parents who may have concerns about getting their child a full-featured and expensive smartphone. Location monitoring is the watches' main purpose, but many also allow a parent to call or text a child. Some send an alert when a child leaves a designated geographical area, a feature known as geo-fencing. And some have cameras that let a parent see what their child is up to.

In the Norwegian report, researchers tested four watches and found that three didn't meet basic security safeguards. The resulting "leakage of customer data" allowed a stranger to find information about a child or children and even contact them without the parent's knowledge. 

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