A student from an Auckland highschool that banned the anonymous messaging app Yik Yak, says downloads of the app boomed one lunch time, and it was swiftly used to bully other students.
The principal of Diocesan School for Girls, Heather McRae said she was really proud of the girls who said too many students were using the app in a negative way.
Phoebe Ellwood said the app was now blocked on the school's wifi.
"It was just in a lunchtime actually just over and hours that it really boomed, everyone was talking about it and everyone was downloading it.
"What happened is a small minatory of girls were misusing it and using it to anonymously bully a group of girls at school."
Ms Ellwood said a group of girls talked the school's senior management team about the app, and they cracked down on it the next day.