Phone use in school can be a distracting nuisance and a bullying tool, educators say. So the devices aren't allowed in an increasing number of districts around the country. Tougher policies are needed, lawmakers and school administrators say, because rampant social media use during school threatens students' education, well-being and physical safety. Classmates have been covertly filmed and mocked on social media, and even assaults have been planned online and videotaped in a few cases. "Cellphone use can fan the flames of any tensions that may exist between students," says Supt. Chuck Leichner of Bolivar-Richburg Central School District in Western New York, south of Buffalo.

More commonly, some pupils text friends during class or use Snapchat, a social app, to joke, gossip and arrange bathroom gatherings to tape dance videos or online challenges. "I call them 'Toilet TikToks,'" says Orlando-area middle school teacher Lisa Rodriguez-Davis. "It was getting out of hand" before a statewide ban took effect this school year, she adds.

Nearly all U.S. public schools have student phone policies, mostly to restrict use during classes. Full bans are "the smartest thing schools can do, and it's about time it got done," New York Times columnist Pamela Paul wrote last week, adding: "A new study by Common Sense Media found that 97 percent of teen and preteen respondents said they use their phones during the school day, . . . primarily for social media, gaming and YouTube."

That's changing in some areas. Under the six-month-old Florida law, public school districts now ban student phone use during class time and must block Wi-Fi social media access. (Students can keep silenced phones or tablets in backpacks.) The county that includes Orlando went further this fall, barring phone use during the entire school day, including between classes and lunchtime -- a move also made by districts in South Portland, Maine; Allegheny County, N.Y.; Charlottesville, Va., and others. A new phone policy at Hillsborough County Public Schools in Tampa warns students: "We See It — We Take It."

Critics say the bans keep teens from doing online research or taking college-credit classes during free periods or lunch hour. The restrictions also hinder communications for high schoolers with family responsibilities or after-school jobs, some parents and students complain. Another gripe is the inability to snap photos of art class projects. Drawbacks are a worthwhile tradeoff for seeing more engaged, focused students, administrators insist. Cellphones are "a tool a lot of kids can't manage properly," says Heather Whitney, school board chair in Claremont, N.H. "Inappropriate pictures were being taken and there is cyberbullying." The local high school this year gave students a secure pouch for storing phones until dismissal each day.

Student says: "They expect us to take responsibility for our own choices. But then they are taking away the ability for us to make a choice [about phone use] and to learn responsibility." -- Sophia Ferrara, senior at Timber Creek High in Orlando

Legislator says: "This [school day ban] is one step to help protect our youth and our kids from the grips of social media. It's also going to create a less distracted classroom and a better learning environment." – Brad Yeager, Republican state representative from Port Richey, Fla.

Teacher says: "I love that when you go into the cafeteria, they're not looking on their phones and just mindlessly eating." -- Lisa Rodriguez-Davis, middle school teacher in Orlando, Fla.