"Social media can be as intense as the old-fashioned way of meeting people in person. These days people can meet at the drop of a hat and the underlying threats in this case were very real. She did something you didn't like, you blackmailed her. She was vulnerable."
Chris Hails, from internet safety group NetSafe, welcomed the sentence, saying Judge McDonald had sent a strong message that such behaviour had serious consequences for the victim and could lead to jail for the abuser.
"There has been a rise in complaints to NetSafe about this type of social media activity and the judge's comments show that the courts take this type of offending seriously," Mr Hails said.
"Young people can be vulnerable on social media, which is deeply involved in every aspect of their lives. [The sentence] will leave no doubt that this kind of offending can lead to jail."
He said the number of complaints to NetSafe about such activity from around the country had increased in recent years, with complaints from Northland in the top three.
"Last year we had almost 8500 complaints nationally, including 283 reported from Northland. That's a 22 per cent rise on 2014 [231 complaints], which is in the top three for rises last year along with the West Coast and Manawatu," Mr Hails said.
"This shows those who do this that they can be found and they will be punished."
He said parents and caregivers needed to take a close interest in their children's social media activity, and make sure youngsters had somebody they could talk to if they felt unsafe or had concerns about any social media contact they were getting.
"It's vital that they are aware of the risks and dangers of social media. Keep lines of communication open with your young ones.
"Technology is not a bad thing and if parents try to stop their kids from using it they will do it elsewhere," Mr Hails said.
"It's great that in this case the girl felt she had somebody she could go to about this treatment."
