What would you do if you found out that someone had posted naked pictures of you online, without your permission? It's known as "revenge porn", and in the age of mobile phone cameras and sexting, more and more people are becoming victims. Some are fighting back.

Hollie Toups remembers in vivid detail the day that changed her life. The 33-year-old Texan was at work last year when a friend called to tell her there were naked pictures of her on a website.

"I left work and came home and ran upstairs and opened my computer," she tells me at her home in the small town of Nederland in south-east Texas. We're sitting on the same couch where she first typed in the address of the site - Texxxan.com.

A few clicks later Toups was looking at topless photos she'd taken for an ex-boyfriend when she was 24. And not just photos - posted alongside them were her name, links to her Facebook and Twitter accounts, a Google map of her location and a stream of comments.

We don't want money, we want them to be held accountable Hollie Toups

"If you take every negative emotion, it was all of those at once," she remembers. "As you're looking, people are in real time commenting on your photos, saying things like you need to be raped."

"I was in tears for days," she tells me. She was afraid to leave the house, and when she eventually did, she was approached several times by men who had seen the photos.

"You're being judged and shamed," she says. "It erases the unspoken boundary of strangers, people think they know who you are and what you want, they approach you at will."

Toups initially suspected her ex had posted the photos. As the term "revenge porn" implies, it's the most common way images end up on these sites.

But among the photos posted online were some she had taken but never sent to anyone. Somehow her photos had been hacked or stolen.

Revenge-porn hackers may raid email or cloud storage sites to steal photos of a woman they have targeted, but Hollie thinks that in her case they may have been downloaded when she left her phone for repair.

It turned out she wasn't alone. Dozens of women in the area were finding their pictures on Texxxan.com, and suffering similar consequences. Some lost their jobs or their relationships. One contemplated suicide.

Desperate to get their photos off the internet, Toups and the other women went to the police and lawyers. But the response was generally the same - they were told there was nothing they could do, and they shouldn't have taken the photos in the first place.

Find out more Image caption The attackers got access to the servers underpinning the porn site James Fletcher's Assignment The Revenge Porn Avengers is broadcast on the BBC World Service on Thursday 12 December from 00:32 GMT Listen via BBC iPlayer Radio Browse the BBC World Service documentary archive

Eventually Toups was given the name of a local private investigator, Philip Klein. She dropped everything and drove straight to his office.

"It was like he saved my life, I just wanted to hug him," Toups remembers. "I was just a hot mess is the only way to describe it and he was the first person who said 'I can help you, we're gonna fix this.'"

But there was a problem. Running a revenge-porn website raises a "hodge-podge of legal questions", Klein says. But it is not necessarily illegal.

Working with the investigators, Toups and the other women turned up a number of potential violations of the law. Some of the women were under 18 when the photos were taken, making the pictures child-pornography.

Some of the women claim that when they asked the site to take their pictures down, they were asked for money to do so - potential cases of extortion.

Another option, if the women took the pictures themselves, was to copyright them, then go to court if the website refused to take them down.

But if the law was being broken when the pictures appeared on the website, it wasn't clear who was responsible. Primary responsibility would be with whoever posted the photos, but tracing these often anonymous users can be a long and technically difficult process.

We protect the rights of the nasty people in order to protect the rights of the rest of us Mark Bennett, Criminal lawyer

It would be far easier to go after the site owners and hosting company. But under US law (S230 of the Communications Decency Act), websites and hosts have broad immunity from legal responsibility for content posted by users. This is why Facebook and YouTube are not legally responsible for your comments or videos.

The investigators managed to identify the owner of Texxan.com, 25-year-old Hunter Taylor. Research revealed he'd starred in porn films, hiding behind a pseudonym - a privilege not granted to the women pictured on his website.

But for Hollie Toups the most shocking discovery was that Taylor and another man alleged to have helped him run the site lived just a short distance away.

"I could not catch my breath, I was on the verge of a panic attack," she tells me. "You always assume someone orchestrating something this big or malicious is from somewhere else, but to find out they're from your home town, to find out one used to date a friend of mine was completely overwhelming, for all of us."

Eventually the child porn allegations were enough to convince the web-hosting company to shut down Texxxan.com early this year. The FBI is said to be investigating.

Hollie Toups and dozens of other women have also launched a class-action civil lawsuit suing for damages under Texas invasion of privacy laws. It targets the site owners, the web-hosting company, and some of the men who allegedly posted images.

So far the women have succeeded in getting an order stopping Texxxan.com from re-opening or reposting content. But the website immunity law poses a huge hurdle, and many commentators argue the case will ultimately fail.

Image caption Hollie Toups is determined to continue her campaign

Hunter Taylor declined to be interviewed. But in his deposition for the court case he claimed sole responsibility for running Texxxan.com and said he had done nothing wrong. He denied charging money to remove photos and said the site was simply a platform for users to post what they wanted.

In some ways the Texxxan.com story is unusual, because the victims, the site owner, and many of the people posting images were all living in the same part of the world.

But the experience of Hollie Toups and the other women is typical of victims everywhere, and over the past year more and more of them have been coming forward to tell their stories.

It's given a human face to the issue, and triggered a fierce debate about how best to deal with revenge porn.

Many victims in the US want to see it criminalised at the state and federal level, and the immunity of site-owners taken away.

The victim-blaming is shocking, it's bringing us back to the days of blaming the rape victim Charlotte Laws, Campaigner

"We don't want money, we want them to be held accountable," says Hollie Toups. "Take someone's freedom away and they'll think twice and it's a lesson to other people."

Lawmakers throughout the United States appear to be listening. Bills criminalising revenge porn have recently been introduced in Wisconsin, New York and Maryland, and have already been passed in California and New Jersey.

The California legislation doesn't cover self-taken shots, however, which some campaigners claim may represent up to 80% of all revenge porn.

"There wasn't a lot we could do about it," says Charlotte Laws, who campaigned for the California law after her daughter's photograph was posted on a revenge-porn site.

"It was either ditch the whole idea, or pass what we could and patch it up later, and sometimes you have to do that in politics."

But should the criminal law be getting involved at all? Mark Bennett, a Houston criminal lawyer and self-described "first amendment extremist", agrees that revenge porn is undesirable, but argues it's still constitutionally protected free speech.

"We protect the rights of the nasty people in order to protect the rights of the rest of us," he says.

"If we start to make an exception because the guy who posted the images is clearly a nasty human being, then we give the government license to decide who the nasty human beings are and who the nasty human beings are not. And I don't want the government to make those sort of decisions.

"That's the bottom line. Not every wrong is a crime, nor should it be."

'The net's most hated man' Hunter Moore's business plan was simple: he got rich by publishing pornographic pictures of men and women without their permission. Below each post appeared a stream of comments from visitors critiquing - to put it lightly - the victim's looks and body. If anyone complained, they were ridiculed. If they threatened legal action, Mr Moore ignored it. As many of the site's victims soon discovered, they were largely powerless to do anything about it. IsAnyoneUp's Hunter Moore

Much of the debate isn't as carefully crafted. After the law was changed in California, Hunter Moore - who founded the now defunct revenge-porn website IsAnyoneUp - took to YouTube to vent his feelings.

"Oh the girl crying because she sent titty pics to some fool who put it on the internet," he said in an expletive-laced video.

"Why would you protect those people... How about this, you take responsibility for your actions and stop pointing the finger at other people."

It's a consistent theme in the debate about revenge porn - if you don't want your pictures on the internet, don't take them in the first place. Campaigner Charlotte Laws strongly disagrees.

"People have a right to take photos of themselves if they want to," she says.

"Thirty or 40 years ago people took polaroids, but if someone broke into their house and stole the picture, I don't think society would say it's your fault. The victim-blaming is shocking, it's bringing us back to the days of blaming the rape victim."

So what would Hollie Toups change if she could travel back to her 24-year-old self, camera in hand?

"Nothing!" she says decisively. "I didn't do anything wrong. Thousands of people have tried to make this my fault and I'm very stubborn."

It will take a lot more stubborn determination if she and other campaigners are to achieve their goal of state and federal laws against revenge porn.

They see it as a quest for justice, but their success or failure may also help shed light on this key question of our times: as the pace of technological change creates previously unimagined pitfalls, is it the law or human behaviour that needs to catch up?

James Fletcher's Assignment The Revenge Porn Avengers is broadcast on the BBC World Service on Thursday 12 December from 00:32 GMT. Listen via BBC iPlayer Radio or abrowse the BBC documentary podcast archive.

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