Parting from someone you love is never easy. It often means watching the affection and intimacy you once shared turn into bitterness and resentment. It often means sorting out who sees the children when, who lives where, and who gets what.

Now imagine that in addition to all that sorrow and chaos, you discover that the person you once loved and trusted has taken your most intimate, vulnerable moments and turned them into sexual entertainment for strangers.

With the click of a button, an intimate photo of you can be uploaded to a website where thousands of people can view it and hundreds of others can share it. In a matter of days, that image can dominate the first several pages of search engine results for your name. It can be sent to your family, your employer, your co-workers, and your peers.

We know this as "revenge porn", and its rise has drawn the attention of lawmakers across the globe. Last week, Wisconsin became the third US state to pass an anti-revenge porn law just this year (after Idaho and Utah).

Revenge porn, more accurately described as nonconsensual pornography, is the distribution of sexually explicit images without the individual's consent. It's a serious form of harassment and often a form of domestic violence. Victims are routinely threatened with sexual assault, stalked, harassed, fired from jobs, forced to change schools, even forced to change their names. Some victims have even committed suicide.

At a fundamental level, nonconsensual pornography is an extreme invasion of privacy, one that causes serious and often irreversible harm to a person’s physical and emotional well-being, damage to their reputations, and can even threaten their financial security. As modern societies, we impose criminal punishments for far less. We punish theft, drug possession and destruction of property. So why don't we punish revenge porn?

In some ways, it’s an old story. The majority of victims are female; the majority of perpetrators are male. In other words, like domestic violence, sexual assault, and sexual harassment, nonconsensual pornography disproportionately affects women and girls. But it's also the kind of offence that has historically been taken less seriously, and for which it is victims rather than the perpetrators who are routinely blamed. Victims are told that they should never have taken or shared the images to begin with, and that by consenting to be seen naked by one person, they are effectively agreeing to being seen by the entire world.

This position is both morally bankrupt and hypocritical. People rely on the confidentiality of transactions all the time: we trust our doctors with sensitive health information; we trust salespeople with our credit cards; we trust banks with our earnings. We are able to rely on the confidentiality of these transactions because it is taken as a given in our society – most of the time – that consent to share information is limited by context. That intuition is backed up by the law, which recognizes that violations of contextual consent can and should be punished.

This should be especially true for sexual consent – the lack of consent makes the difference between sex and sexual assault. And laws against sexual assault and voyeurism recognize the right of people to control when, how, and by whom they are exposed in their most intimate moments. Everyone has this right to privacy and this right to choose – and this is why we need laws against nonconsensual pornography.

But we must be careful in crafting these laws – we need to be clear about what we are punishing and how we define the crime. As the Cyber Civil Rights Initiative model statute reflects, the law should criminalize the intentional distribution of sexually explicit images of a person without that person’s consent. The focus on consent is vital, and shouldn't be obscured by focussing on the perpetrator's intention – whether they intended to harm the victim, or whether they did this for their own entertainment or profit shouldn't matter. Such requirements are misguided, as they detract from revenge porn’s real harm: what matters most is the perpetrator intentionally violated the sexual consent of the victim.

In the US, it's especially important that such laws are designed to deter and punish malicious invasions of sexual privacy without punishing or chilling otherwise innocent or protected expression under the First Amendment. This means that the law would include some important exceptions – it wouldn't apply to images taken of people voluntarily exposing themselves in public or images from commercial pornography. It wouldn't apply to posting a picture of a flasher on a website to warn others. It wouldn't apply to a friend sending a link to a person to warn them that their image has appeared on a revenge porn site. It wouldn't apply to an image disclosed to report on a matter of public interest. It would never apply to merely “embarrassing” photos of people in their underwear or in bathing suits.

It would, however, apply to a vengeful ex who sends a nude picture of his former partner to her employer or uploads it to a revenge porn site. It would apply to the person who obtains nude images of people via hacking or theft and uploads them to Twitter. It would apply to people who secretly record sexual activities of or with another person without their consent and post the recordings on YouTube, or to images of sexual assault posted to Facebook.

Lawmakers across the globe are beginning to recognize the need to deter this destructive conduct. Israel recently criminalized revenge porn and Canada, Brazil, and Japan are taking similar steps. In the US, seven states have criminalized the practice while 18 more have pending bills (Illinois and Arizona will treat it as a felony) and a federal bill is being proposed by Congresswoman Jackie Speier. (Mary Anne Franks, one of the authors of this piece, has worked with many of these state legislatures and with Rep. Speier’s office.)

Revenge porn doesn't just harm individual victims. It also reinforces dangerous social attitudes about sexual privacy and autonomy. Revenge porn is, among other things, a powerful means for men to punish women for making choices they don’t like. But no one, man or woman, should have to fear that the price of engaging in sexual intimacy will be a ruined life.