“People say, ‘Oh, just log off. Don’t read it. Turn off the computer,’” says Heller, who turned her personal experience from 15 years ago into a legal speciality as a leading expert on online harassment.

“This is the 21st century, and people have a right to use the internet for work, for pleasure or to express themselves. Telling people not to read the comments is no longer enough. We don’t talk enough about this problem, and we need to.”

Online harassment has become such a familiar part of the internet that it can be hard to imagine the web without it.

From teen cyberbullying to authoritarian governments silencing dissent, online toxicity is a fact of life for everyone, with women, teens and religious and racial minorities the most likely to be targeted. And there is evidence the problem is getting worse.

In 2014, 15 per cent of Americans said they had faced severe or significant online abuse, defined as stalking, physical threats, sustained harassment or sexual harassment. In 2021 that number was 25 per cent, according to studies by the Pew Charitable Trusts.

Health-care workers, journalists, teachers, police and government workers have all reported increases in online harassment in recent years, as the pandemic and political polarisation led many people to release their anger and fear online.

Nearly three in four female journalists reported receiving threats or other forms of online harassment, according to a survey by Unesco and the International Centre for Journalists that polled more than 700 journalists in more than 100 countries. One in five of those said the harassment escalated to offline abuse or even assault.

The growth of the internet has also expanded the ways that people can be targeted: social media posts, direct messages, texts and streaming video. And with the rise of smartphones and cheap, ubiquitous internet, harassment can now be a 24/7 problem for victims.

“We’ve made so many strides – there’s more awareness now – but it’s easy to get frustrated and to feel like we’ve got nowhere,” says Tina Meier, who started a foundation to teach kids and parents about online harassment after her daughter’s suicide in 2006.

Thirteen-year-old Megan Meier had been bullied by someone she met online who she thought was a teenage boy named Josh. The two had flirted until the person suddenly turned against Megan. “Everybody hates you,” “Josh” wrote. “The world would be a better place without you.”

Police later determined that “Josh” was actually an adult woman, the mother of one of Megan’s classmates.

Women are more likely than men to say online harassment is a serious problem, Pew found. They’re also more likely to report being the victims of online sexual harassment and more serious abuse such as threats of physical harm.

The difference is so great that many men may not understand the severity of the demeaning language, sexualised insults and unwanted attention that women frequently face online.

A coordinated harassment campaign against female video game designers that began in 2014, known as Gamergate, became so pervasive – including threats of rape, torture and murder – that some women hired security or went into hiding.

Online harassment has also been used globally to attack journalists, dissidents and others in the public arena.

Anonymity can make it easier to be cruel without fear of offline repercussions. It’s a phenomenon called the online disinhibition effect, and it’s one reason why trolls feel comfortable saying things they would never say to someone in person.

Tech companies say they are getting better at identifying and stopping harassment. For example, Instagram, which is owned by Facebook parent company Meta, made several changes designed to reduce harassment, including putting warning labels on potentially abusive language and making it easier to block or report harassers.

Yet those moves haven’t been enough. Internal Facebook documents leaked by former employee Frances Haugen show that executives are aware of the potential for their products to be used to harass people. One internal study cited 13.5 per cent of teen girls saying Instagram exacerbates suicidal thoughts and 17 per cent saying it worsens eating disorders.

“Online harassment is a problem for everybody, but I think it’s especially problematic for kids,” says Natalie Bazarova, a professor at Cornell University who studies social media.

She said a multifaceted approach is required to address the problem: legislation to require minimum safeguards from tech companies, technical innovations and extensive educational efforts such as simulations that teach teens to spot cyberbullying and use social media safely.