More than 50 victims have offered the police screen shots of derogatory or insulting comments about them left on the Instagram account, which asked people to spread gossip about others' sexual activities.
In all, about 85 teenagers have reported other teens' comments about them and their private lives to the police.
Many of the comments, several of which used graphic and obscene language, are being investigated as possible slander.
At the time, in late December, the mud-slinging on the popular photo-sharing site seemed to be the straw that broke the camel's back for teenagers fed up with accusation and counter-accusations online.
The original account holder, who had a pseudonym, had also promised the ratting teens anonymity - a promise that was reportedly broken, with ensuing pandemonium.
A riot ensued as hundreds of students assembled outside the Plusgymnasiet high school in an attempt to find the owner of the anonymous Instagram account - at the time believed to have been a 17-year-old girl, whom the police had already taken to safety earlier in the day.
Video from the scene
She was later cleared of all suspicions.
Police made 27 arrests as some teenagers engaged in vandalism and resisted orders. A smaller mob the following day also caused enough of a commotion to lead to several arrests.