How often do you post a picture of your child on social media sites such as Facebook and Twitter? It may not be the smartest idea, especially if your posts aren't limited to only your network of friends or followers.

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These innocent photos can fall into the wrong hands and be used in the least innocent of ways.

According to Lt. Glenn Ross of the New Jersey State Police Cyber Crimes Unit, "you don't have any control" over what other people do with a photo of your 6-year-old. Unfortunately, he said, there are bad actors out there looking to gain something from posts you consider cute and harmless.

In an instant, a stranger can doctor a photo of someone's child, place them in a sexual or otherwise inappropriate scenario, and demand ransom of the parents. It has been done.

"'Pay us this money or we're going to put this out there,'" Ross said of these people. "People can take these pictures and they'll do whatever they want to them."

A phenomenon known as "digital kidnapping" has also been cited, in which someone essentially steals another person's child by resharing their photos as if the child were their own.

Ross noted, though, parents don't only have to worry about complete strangers. People in their own networks could be a threat as well. Embarrassing photos can be used as ammunition between competitive parents.

"They may want to embarrass you and send this out to the school or to other parents," he said. "You're looking at an embarrassment factor, harassment factor. There could be something criminal to it."

In the newest University of Michigan C.S. Mott Children's Hospital National Poll on Children's Health, an overwhelming majority of parents expressed concern that their child's privacy would be compromised due to online postings. Nearly three-quarters cited a parent who "overshares" online, including information that identifies a child's location.