A woman hacks her ex-boyfriend’s Facebook account to post a picture of herself in hospital after he attacked her with a baseball bat. A teenager protests against the lenient sentence given to her rapists by tweeting their names in a deliberate breach of the judge’s order. A woman living with a disability uploads a secretly recorded video to YouTube of her father, a magistrate, physically assaulting her.

What do these cases have in common? They all involve girls and women using the internet to accuse others of violence and abuse - including people who have not been convicted of any crime. These cases can challenge basic legal principles such as the presumption of innocence and raise questions about false allegations. But I think this kind of online revenge can be good for victims.

The courts are meant to be the right place to air claims of victimisation but they can treat girls and women terribly. Professor Sandra Walklate goes so far as to say that it is “imaginary” to believe that the police and the criminal justice system are the solutions to gender-based violence – in fact, these agencies have often been part of the problem.

Research from around the world finds that many police, lawyers and court “experts” believe that girls and women invent false allegations for attention or advantage, or out of stupidity or delusion. No wonder victims are reluctant to report and often drop out of legal proceedings along the way.

When the justice system fails, then “old media” (such as newspaper, television and radio) is supposed to provide other spaces in which injustice can be aired and addressed. But this kind of media is tightly controlled and victims can struggle to get their issues onto the agenda.

The male-dominated processes of news production have long been concerned with the risk of “false allegations” to men. Coverage of victims can be sceptical, voyeuristic or just plain awful. And if victims don’t like the way they have been portrayed there isn’t much they can do about it.

That has all changed with the internet. Suspicious of the justice system and “old media”, some victims are using blogs, websites, Twitter, Facebook and other online platforms to document their experiences. By going online they can control the way that they represent themselves and how they tell their story.

It can prove difficult to prosecute online speech so victims may, if they want, name their attackers with relatively limited risk of defamation action. This would seem to breach important social values and legal norms. However many of these norms and values fall short in practice, leaving victims with little option but to look for alternative options if they want to testify to their experiences.

Of course, there is no guarantee that every tweet or status update about victimisation is going to be accurate. A claim can be malicious, a digital photo can be faked and a video can be staged. I don’t think it’s ideal that some victims feel they have to go online to get public recognition. But given the barriers posed by the justice system and “old media” I don’t blame them.

More than that, I have to admit that it’s a guilty pleasure when, for instance, a 17 year-old “St Kilda schoolgirl” uses Twitter, Vimeo and Blogspot to dance circles around football players who apparently thought they could treat her like another “groupie”.

We usually think about revenge in terms of pettiness or malice, but it can give voice to legitimate outrage and highlight inequality. This kind of online revenge can start conversations about violence against girls and women away from the limits imposed by judges and journalists. It can activate and mobilise support for victims. In some cases, it can force courts to change their ways and this has a positive impact on “old media” and the community too.

So revenge can be political as well as personal - but it can also be healthy. Research shows that being listened to, and feeling supported and validated, reduces the mental health impact of being victimised. On the other hand, being silenced or disbelieved can result in worse outcomes for the victims.

Given the close link between gender-based violence and mental illness in women, victims who use online technology to create new opportunities to speak and be heard may be protecting their right to health as well as justice. It is true that they are exercising these rights in new and sometimes troubling ways, but they are also forcing change to those institutions that have been reluctant to address their needs.