Last week, a British serial sex offender was jailed for four years after attempting to get a New Zealand teenager to send videos of herself performing sexual acts.
Wolverhampton man Gavin Rhodes, in his 30s, was banned from using computers to contact any girl under 16, but he used the Kik messaging app on his girlfriend's computer to contact the 14-year-old Kiwi.
Kik, a free app developed in Canada, asks users for a name, username, date of birth and email address.
People are found by username or through phone contacts. Some third-party websites, plastered with pornographic banner ads, offer to find "Kik friends" by age and gender.
Kik says it takes user safety seriously and works closely with Police.
Warren Ferdinandus, director of child exploitation prevention group ECPAT Child Alert, said new instant messaging apps presented significant child safety challenges.
Ferdinandus said New Zealanders visited known child abuse imagery website 50,000 to 60,000 times every day. But apps or email were also used by predators who could easily blackmail underage girls and boys who'd sent explicit pictures.
"There's a huge issue around shame and personal image."
Netsafe executive director Martin Cocker said messaging apps like Kik could be used by sex offenders anywhere in the world to target children here.
"Criminals have the upper hand in terms of technology [enabling] them to be agile and find victims very quickly. By comparison, law enforcement is heavy on processes and legal requirements," he said.
"It's important for parents and families to recognise that wherever young people are known to congregate, so too are predators that wish to connect with young people."
He said it was important to know how to respond when online "friends" asked for nude or sexual content. Cocker added that users, guardians, app developers and law enforcement were all responsible for keeping children safe online.
"When things go wrong it's often because many of these parts didn't function as well as you'd like."
Kik spokesman Rod McLeod said the company had a "24/7 support team" and offered blocking and reporting tools to help users to flag unwanted content or contact.
McLeod said if the company were approached by police it would work with law enforcement to "combat child predators anywhere in the world, either upon provision of a court order, or in emergency situations."
He said the company constantly communicated with police forces while respecting user privacy.
"From our records, law enforcement did not reach out to Kik for this incident," he said.
Nicole Madison Lovell, 13, was kidnapped and murdered in the United States in January after meeting two college students on Kik.
In England, Rhodes was caught after changing his address without telling authorities. A probation officer searching for him discovered the Kik exchange.
Wolverhampton Crown Court said Rhodes was charged with making an indecent photo, and attempting to incite a girl to engage in sexual activity.
He was sentenced to four years' jail and a sex offenders' prevention order indefinitely.