About 30 per cent of young people in the U.S. have been involved in some form of "sexting" and nearly half of those say they don't see it as a serious problem, a survey suggests.

Sexting, a term that combines the words sex and texting, is the sharing of sexually explicit photos, videos and chats by cellphone or online.

The survey, conducted by Knowledge Networks for The Associated Press and MTV, polled 1,247 people between the ages of 14 and 24, and found 18 per cent said friends had sent them naked pictures or videos of themselves.

Eight per cent said they'd been sent naked pictures or videos of someone else that they knew, and 14 per cent said they suspected those pictures were shared without permission.

Seventeen per cent of those who received naked pictures said they passed them along to someone else, often to more than just one person.

The survey, which is part of MTV's campaign, A Thin Line, to help stop the spread of digital abuse, has a margin of sampling error of plus or minus 2.8 percentage points.

Sexting has been linked to at least two suicides in the U.S. Last year an 18-year-old Cincinnati woman hanged herself after weeks of ridicule at school; she had sent a nude cellphone picture to her boyfriend, and after they broke up, he forwarded the picture to other girls.

Three months ago, a 13-year-old Tampa Bay girl hanged herself, after relentless taunting at her school. She had sent a nude photo of herself to a boy she liked, and another girl used his phone to send the picture to other students who forwarded it along. The St. Petersburg Times reported on the girl's death this week.

"There's definitely the invincibility factor that young people feel," said Kathleen Bogle, a sociology professor at La Salle University in Philadelphia and author of the book Hooking Up: Sex, Dating and Relationships on Campus.

Beyond feeling invincible, young people also have a much different view of sexual photos that might be posted online, Bogle said. They don't think about the idea that those photos might wind up in the hands of potential employers or college admissions officers, she said.

"Sometimes they think of it as a joke; they have a laugh about it," Bogle said. "In some cases, it's seen as flirtation. They're thinking of it as something far less serious and aren't thinking of it as consequences down the road or who can get hold of this information. They're also not thinking about worst-case scenarios that parents might worry about."

Boys were a little more likely than girls to say they received naked pictures or video of someone that had been passed around without the person's consent. Common reasons were that they thought other people would want to see, that they were showing off and that they were bored.

Girls were a little more likely to send pictures of themselves. Yet boys were more likely to say that sexting is "hot," while most girls called it "slutty."

With files from The Associated Press