UNION, N.J. (CBS News) – For most kids, receiving their first cellphone doesn’t come with a set of instructions on how to protect their privacy. Some experts say the riskiest time to give a child a cellphone is in middle school, but new data from Common Sense Media released early to CBS News says 84 percent of kids have smartphones by 13 or 14 years old.

Now, an experimental new curriculum offered at a handful of schools in the New York area aims to teach kids how to use them safely. Teachers are hoping students walk away with an important lesson: overusing devices can lead to oversharing, and oversharing can lead to trouble.

Beyond the fun of Snapchat streaks and Minecraft marathons, a group of fifth grade students at St. Michael’s School in Union, New Jersey, are benefiting from a curriculum rarely taught, reports CBS News’ Meg Oliver.

Seton Hall law professor Gaia Bernstein designed the class for this pivotal moment in modern life. A study shows 50 percent of teens feel they are addicted to their mobile devices.

“I think family life was changing, relationships were changing, and parents were getting worried,” Bernstein said.

Although some of the kids this curriculum targets don’t even have phones yet, she believes there is value in the moment when kids are getting their first phone – or are just about to.

“It’s much harder to influence people who already made choices, who are completely embroiled in social networks. We thought there’s this moment, when you get your first cellphone, where the kids are more likely to listen,” she explained.

More likely to listen, start talking and hopefully begin to understand how their actions online can impact their daily lives.

Eleven-year-old Eva Zazzalli graduated from the class earlier this year. She got her first phone a few months ago and already has three Instagram accounts – one solely for slime.

“I’m actually not on it as much as people are. ‘Cause I’m always, like, going on the phone and I see, like, 20 text messages. I’m, like, where did that come from?” Eva said.

Eva’s parents trust her to use judgment when it comes to her phone, but her mom stresses one important lesson.

“Remember every photo, every text is indelible. And when you send that out, in 10 seconds or less, it’s in cyberspace for everyone to read, to see, it can go all over the world,” Linda Perillo Zazzali said.

The digital privacy class at her school hammered that point home.

“The most important thing I learned was probably, like, to be aware that some of the stuff you post affects other people,” Eva said. “So I always make sure with my friends if it’s OK if I post something with them, or they always ask me. … I learned that a lot of the stuff I thought I was doing that was safe, was really not.”

To graduate from the program, the students had several homework assignments. One was to turn their phone off for an entire weekend. The other was to download the Moments app, which tracks how much time they spend on their devices. The students we spoke to were surprised at the number of hours a day they actually spend online.

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