The online abuse is so frequent that the lawyer and anti-Islamophobia advocate wouldn't get any work done if she reported it all to police.

"I think about the consequences of reporting, the time and effort that goes into it, the psychological impact it has on me to pursue these matters, the potential outcome and whether it's all worth it," she said.

But just before midnight one night last July, a message landed in her Facebook inbox that she didn't ignore.

"Watch as we come for you in your sleep cut your throat as you do the animals you torment," it said. "Kill your family for you to see. Kill your uncle which is now your husband slash grand f---er.. I will find you and hunt you down."

In one of very few cases of online abuse that are prosecuted, Trina Pania Hohaia, a 38-year-old mother from Guildford, was convicted in her absence in Hornsby Local Court in September. The Reclaim Australia supporter, whose name and image were visible on her profile, was fined $1000.

Online abuse has become pervasive yet the number of criminal convictions cover a mere fraction of the hateful material flung around the world wide web.

Figures provided to Fairfax Media show charges for using a carriage service to menace, harass or offend – the antiquated piece of legislation that online abuse falls under – have doubled in five years.

Last year, there were 1111 convictions from 1585 charges in NSW although the figures are not broken down by web or telephone threats. The most common punishment was a fine of about $700, far from the maximum prison term of three years.

This week, two high-profile cases ended in guilty pleas. Central Coast chiropractor and former Liberal Party member Chris Nelson, 64, admitted to posting racist abuse on the Facebook page of Indigenous politician Nova Peris, and 25-year-old labourer Zane Alchin admitted to a torrent of rape and death threats sent to a group of Sydney women.

However, three in five Australian adults say they have been the target of online abuse and harassment, a 2015 RMIT study found.

"When I started research in this area, you had to go out of your way to find online abuse. Now it's so bad, you have to go out of your way to avoid it," Emma A. Jane, a UNSW academic conducting a three-year study into online misogyny, said.

"It's become a lingua franca online. If you don't agree with a woman, you send a rape threat or tell her she's too ugly to rape. It's so common it's become almost banal."

The internet, particularly social media, has brought empowerment and opportunity but it has quickly become a double-edged sword.

Eight-five per cent of women told the United Nations Broadband Commission for Digital Development last year that the internet provides them with more freedom, yet 73 per cent said they had been abused online.

Anti-semitic and anti-Muslim abuse take up the lions share of reports made to the Online Hate Prevention Institute's Fight Against Hate. Misogynistic and homophobic abuse follow closely behind.

OHPI chief executive Andre Oboler​ said social media had amplified and emboldened pre-existing bigotry.

"People who feel isolated, who may have racist views but keep it to themselves because the people around them don't support it, will easily find people who agree with them online so suddenly their inhibition drops," he said.

While the internet's veil of anonymity allowed a culture of abuse to develop, both Alchin and Nelson posted abuse under their own profiles. It has "become normalised to the extent ... people seem quite happy to do it under their own names now," Dr Jane said.

This is fuelled by the perception there will be no real-world consequences, she said.

Only 10 per cent to 20 per cent of offensive content reported to Facebook and Twitter is removed, OHPI found, and the impacts can be detrimental.

A father who used Facebook to post messages of support for refugees told Fairfax Media that hateful responses from far right groups over the past 18 months escalated to phone calls to his wife. Fake profiles and offensive memes with his image have been spread online. He fears it will affect his future job prospects and his family's safety.

The 47-year-old, who asked for his name to be withheld, said he was laughed out the door when he reported it to Hobart police. "But in the same breath they said they get a lot of Facebook-related suicides," he said.

Of the 50 women Dr Jane has interviewed, none had a satisfactory response when they reported online abuse to local police. Some were told to take a break from Facebook or to change their profile picture to "something less attractive".

Paloma Brierley Newton, the subject of Alchin's abuse, was initially turned away by Newtown police. She had stepped in to defend a friend whose profile from the dating app Tinder was being shamed on Facebook for being too provocative.

It was only when she set up an advocacy group with her friends, Sexual Violence Won't Be Silenced, and went to the media that police became interested.

She hopes to introduce training to all local police stations, where cases of online abuse are investigated.

Assistant Commissioner Gary Worboys, corporate spokesman for victims of crime, said victims of online threats "can and should expect the complaint to be taken seriously".

"While there is no ... legislation in Australia that is specifically for cyber bullying, there are existing laws police use," he said.

While prosecutions are important, Dr Jane said we needed to address the reasons why people posted abuse.

"We're still a long way from cultivating a culture of accountability online," she said. "There have been massive institutional failures at the level of corporations, social media platforms, police and policy makers."