Naked pictures being shared on an app where messages are designed to disappear in seconds are being saved and widely reposted online at an alarming rate.
Girls and young women are increasingly being left distraught after finding naked photos and videos sent privately on popular social media app Snapchat have later been widely circulated after photos were saved using a screenshot.
Nearly half of female students spoken to in a new survey said they had had an embarrassing photo put online against their will last year.
The survey, by cyberbullying awareness group Sticks 'n Stones, spoke to 11- to 18-year-olds from 10 schools across Central Otago.
Of particular concern is Yik Yak, which the student anti-bullying project predicts will inflict more harm than the notorious Ask.fm, a website previously linked to a number of teen suicides.
NetSafe's Martin Cocker said most cyberbullying was no longer confined to direct text messages but happened across multiple communications platforms, apps and social media.
It included the anonymous Yik Yak app and Snapchat, the "poster child" for disappearing media.
"We're seeing a growth of bullying strategies that use those kinds of mobile technologies and the fact that your smartphone is a camera and an internet able device all-in-one, you're capturing images of people in embarrassing situations and then quickly posting them up," Mr Cocker said.
"While posting embarrassing images of people isn't something new, the phone, it gives them the option to look for those images or look for those opportunities and then capture it on the spot and then push it out to a large audience straight away.
"Say you were a young person and you wanted to send a naked selfie but you wanted to reduce the risk of it being shared with other people, you send it using that system for a person in the expectation it's deleted at the other end.
"The problem is that for all of those disappearing media apps, a series of other products has been created to capture the media."
There was also no guarantee the person receiving the message was alone.
"The boy says 'could you send me a picture' and you send it to him and he's sitting there with all of his friends. That wasn't what you expected either and that's even without some technological intervention."
Sticks 'n Stones project facilitator Karla Sanders said while Snapchat was posing bullying issues, the evolution of app social networking could eclipse anything they'd seen so far.
"Yik Yak is probably the worst thing I've seen since Ask.fm ... It's absolutely brutal."
She was shocked when she read a vile post on the social app after a runaway was located safe and well.
"The first comment on Yik Yak was, 'It's a shame the little b**** has been found. I had hoped she was being tied and raped by the local paedophile'."
Ms Sanders said Yik Yak was proving destructive in small towns where the mobile app was developing into a place to shame, gossip and share secrets. "When our students have been up in Auckland [and] they've logged on to Yik Yak, there are so many people there ... that there doesn't seem to be the same impact. But if you get somewhere within a small community it's so vicious."
An Ask.fm spokeswoman said it was not a place for abuse or hate and would always hold those who violated policies accountable. This included giving warnings or closing accounts. There were blocking and reporting tools within the app.
A Yik Yak spokeswoman highlighted the app's safety centre which included rules and reporting procedures. Snapchat did not respond to requests for comment.
Photo and video sharing app where an image disappears after seconds. Problem: Images are saved and used to embarrass people.
A popular teen question-and-answer website that allows anyone to post anonymous comments to a person's profile. Problem: Users reveal highly personal information and high levels of bullying.
An anonymous social network app which puts you in contact with people nearby.
Where to get help:
• In an emergency: call 111
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633, or text 234 (available 24/7) or firstname.lastname@example.org or live chat (between 7pm and 11pm) http://livechat.youthline.co.nz/mibew/chat?locale=en&style=youthline
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155 (weekdays 11am to 5pm)
• NetSafe: 0508 NETSAFE (0508 638 723), www.theorb.org.nz