Teenaged kids are handing out more private information on social media than ever before, with little thought for the consequences, a not-so-surprising survey has found.

Teens are carelessly giving away phone numbers, pictures and other sensitive data using their Facebook accounts, the report by the Pew Foundation pointed out.

Ten times more teens now make their phone number available online than had done so in 2006, while the number posting an email address has almost doubled, said Pew.

At the same time, 40 per cent of adolescents have not set up the full privacy settings on Facebook to shutter their stuff from the prying eyes of teachers, advertisers, employers or paedos. About 14 per cent do not bother to use any privacy settings at all, the survey found.

Some 33 per cent of respondents said they were Facebook friends with someone they had never met in person and about one in six said they had been scared by contact with a weird stranger online. More girls than boys were made nervous during a stranger interaction and kids that live in rural settings were also more likely to have encountered someone online that made them uneasy.

The results will be immediately obvious to anyone unlucky enough to have even a passing acquaintance with a member of the teenage horde.

Kids are spending more time on Facebook and Twitter than in previous years, although there is proof that use of Zuckerberg's sociable advertising platform may have reached a plateau, because the number of teens visiting the site everyday has not changed since 2011, at about 25 per cent, with 40 per cent visiting Facebook several times a day.

The report said: "In focus groups, many teens expressed waning enthusiasm for Facebook. They dislike the increasing number of adults on the site, get annoyed when their Facebook friends share inane details, and are drained by the “drama” that they described as happening frequently on the site.

"The stress of needing to manage their reputation on Facebook also contributes to the lack of enthusiasm. Nevertheless, the site is still where a large amount of socialising takes place, and teens feel they need to stay on Facebook in order to not miss out."

Teenagers post the following information on their profiles, according to the Pew Foundation:

91 per cent post a photo of themselves, up from 79 per cent in 2006. 71 per cent post their school's name, up from 49 per cent. 71 per cent post the city or town where they live, up from 61 per cent. 53 per cent post their email address, up from 29 per cent. 20 per cent post their cell phone number, up from 2 per cent.

Researchers also found:

92 per cent post their real name to the profile they use most often. 84 per cent post their interests, such as movies, music, or books they like. 82 per cent post their birth date. 62 per cent post their relationship status. 24 per cent post videos of themselves.

Parents' main concern is still the classic pre-digital stranger danger, only now it's a creepy man behind a webcam they're nervous about, rather than the candy-clutching car driver.

However, one in four parents are concerned about advertisers' access to their children's private information.

Researchers also carried out dozens of interviews with teenagers, leaving in the hundreds of times they used the word "like" in their sentences.

One 13-year-old boy summed up why grown-ups are right to be concerned. “I usually just hit allow on everything [when I get a new app]. Because I feel like it would get more features. And a lot of people allow it, so it's not like they're going to single out my stuff. I don't really feel worried about it.”

Another girl added: “At first, when I got a Facebook, I was worried about my privacy settings, and my parents were too. And then, after I had it for a while, I wasn't really worried as much. So then I took most of them off.”

However, about half of teens have decided not to post something because it might make them look bad in future and just four per cent said they had posted something that caused a problem for themselves or their family.

Some 802 teens were surveyed during the making of the report, which is called Teens, Social Media and Privacy and was released today. ®