Image caption Tulisa Contostavlos told a BBC documentary she found it hard to face people after her ex released a sex tape of her

Thousands of people have had sexually explicit photos and videos of themselves published on the internet without their consent. So why have only a small number of revenge porn perpetrators been prosecuted, and how is the law catching up with them?

While the term "revenge porn" is new, the concept of distributing sexual images of a former partner is not. Before the internet, photos or homemade sex tapes were posted through the doors of friends and relatives.

And there have been reports of vengeful exes submitting photos to pornographic magazines since at least the 1980s.

Numerous celebrities have also had sex tapes released by former partners without their permission. But campaigners say there has been an explosion in revenge porn over the past few years, largely because of the impact of new technology.

A smartphone can be used to make pornographic videos or photos, which can then be shared on social media or revenge porn websites when a relationship breaks down.

Image copyright Hazel Higgleton Image caption Hazel Higgleton said her boyfriend pressured her into making a sex tape

This is what happened to Hazel Higgleton in July 2013, after she split up with her boyfriend.

"I'm sure he put the video on every porn site he could possibly put it on, and then it just went viral and spread everywhere," said Hazel, 25.

"I thought it was something that happens to celebrities. I didn't think it would be an issue for people like me."

Miss Higgleton, from Chelmsford in Essex, said the police were very sympathetic when she reported what she believed was a crime.

However, like many victims of revenge porn, she was told no legal action could be taken.

Image copyright PA Image caption Hazel Higgleton's video was posted on several websites, along with personal details including her Facebook account

"They were so nice about it but they were upset themselves that they couldn't do anything about it," said Miss Higgleton.

"They thought it was terrible that nothing could be done about it, and they believed something had to be changed because they thought it was a very bad thing."

Revenge porn is now being made a specific offence in the Criminal Justice and Courts Bill and the government expects this to become law at some point in 2015, subject to the Parliamentary process.

However, revenge porn can already be prosecuted under several existing laws.

Prosecuting revenge porn

Image copyright PA

Figures obtained by the Press Association showed 149 allegations of crimes involving revenge porn were recorded by eight police forces in England and Wales in the two-and-a-half years between 1 January 2012 and 1 July 2014.

A total of 43 police forces were asked for details of reported incidents but the majority had not held data on revenge porn.

Only six allegations resulted in a police caution or charge

Perpetrators can be charged with harassment. However, this is not always possible as there has to be more than one incident, or the incident needs to form part of a course of conduct directed towards an individual.

Perpetrators can also be charged under the Malicious Communications Act 1988, Communications Act 2003, Protection of Children Act 1978 and the Sexual Offences Act 2003

Find out more from the Crown Prosecution Service

Luke King, from Nottingham, was jailed for harassment in November, after sharing an explicit photo of his former girlfriend using the messaging service WhatsApp.

It was thought to be one of the first revenge porn prosecutions.

Janine Smith, deputy chief crown prosecutor for the East Midlands, hopes it will encourage other victims to report incidents to police.

"Victims don't necessarily understand it's a criminal offence and so this is why it's really good the case has been highlighted," she said.

"Obviously it's traumatic and terrible for the victim but it will say to tomorrow's suspect or tomorrow's victim that we take these cases really seriously."

Image copyright From Luke King's Facebook profile Image caption Luke King was jailed in November in one of the first revenge porn prosecutions

So why was Luke King prosecuted, while police told Hazel Higgleton that no action could be taken against her ex?

Essex Police was asked to comment but said it was unable to find a record of the incident.

Ms Smith said it would not be fair for her to comment on the police but said the Crown Prosecution Service (CPS) "can certainly make sure that we raise awareness within the police".

"We could just highlight our guidance to them, so they are completely aware of our position," she said.

The CPS updated its legal guidance in October to explain how revenge porn cases could be prosecuted.

The law has not changed but the guidance has clarified the different legislation under which a perpetrator could be charged.

Notable cases

Image copyright PA

Shane Webber (above), from Nottingham, was jailed in 2011 for harassment after he distributed naked photos of his girlfriend Ruth Jeffery online. He emailed them to her friends and family and published them on websites

Noe Iniguez was jailed after becoming the first person to be convicted under a new revenge porn law introduced in California. He posted a photograph of his ex-girlfriend, naked, on her employer's Facebook page, alongside derogatory comments

Hunter Moore, who ran revenge porn website isanyoneup.com, was arrested along with colleague Charles Evens in January, following an FBI investigation

Another victim, who asked to be known as Ann, experienced the same problem as Ms Higgleton when she complained to police.

Her ex-boyfriend had been posting naked photos of her on Tumblr for six months when she reported him.

"When I told the police officer he was kind of like 'Oh that's a bit bad, but I'm not sure what that is, or what we could do about it'," said Ann, aged 21.

She wants revenge porn to become a specific offence, but believes the updated CPS guidance will help other victims in the meantime.

"There are cases such as mine which probably could have been covered under harassment because it was done multiple times, but the police were just unaware of how to deal with cases like that," she said.

"I didn't even know the term revenge porn when it happened to me but I started searching for it and found whole websites with thousands and thousands of images on.

"There are over 30 websites solely dedicated to it just in the UK, which is terrifying."

Image copyright Provided by Holly Jacobs Image caption Holly Jacobs founded End Revenge Porn to campaign for new laws, after she was a victim herself

The people featured on the websites - the vast majority of them women - often receive little sympathy.

Holly Jacobs, founder of the international campaign End Revenge Porn, said they were frequently "slut-shamed" and blamed, even by friends and relatives.

"They blame the victim for taking the photos or creating the video in the first place and sharing it with somebody," said Ms Jacobs.

Image caption Tulisa Contostavlos was described as a "slut", "whore" and "slag" on social media

Image caption She told a BBC documentary the release of the sex tape was an "absolute violation of my human rights"

When a sex tape of celebrity Tulisa Contostavlos was released in 2012, she was mainly described on social media as a "slut", "whore" and "slag" rather than as a victim.

One newspaper columnist later asked if she should "take her own share of responsibility" for the tape, which was filmed and leaked by her ex-boyfriend.

But Ms Jacobs believes blame is gradually shifting from victims to perpetrators.

"I think that's in part due to victims speaking up and talking about their experiences, and also getting laws put in place," she said.

End Revenge Porn campaigns for laws in the US and internationally.

"When a law is put in place against a certain act, it sends a message to society that this is a behaviour that won't be tolerated and that is not acceptable," said Ms Jacobs.

Image copyright Getty Images Image caption Revenge porn victim Ann said the reaction to Paris Hilton's sex tape and Jennifer Lawrence's nude photos showed attitudes were changing

Ann said attitudes towards revenge porn had changed, comparing the response when Paris Hilton's sex tape was leaked in 2004 with the release of naked photos of celebrities including Jennifer Lawrence 10 years later.

"With people like Jennifer Lawrence, the main media narrative 'was this is horrific and shouldn't have happened', whereas in previous years, with sex tapes of Paris Hilton and others being released, there wasn't that narrative that this is an abuse," she said.

The Jennifer Lawrence photos were obtained through hacking but the Paris Hilton tape was released by her ex-boyfriend.

"[Then] it was more kind of like 'Oh look at her, she's a bit of a slut'. Now it's like 'Whoa, this is horrendous and this is non-consensual. Stop'."

Despite her own disappointing experience when she went to police, Hazel Higgleton would encourage other victims to seek help.

"It's not you that's in the wrong and you should not blame yourself," she said.

"The other person is only at blame. You should always try and get justice."

Origins of the term "revenge porn"

Image copyright Urban Dictionary

Originally used in the early 1990s to refer to a sub-genre of movies featuring a revenge plot and gratuitous levels of violence, a close relation to "torture porn"

The current meaning was first defined by a user of urbandictionary.com in 2007. JonasOooohyeah defined it as: "Homemade porn uploaded by ex girlfriend or (usually) ex boyfriend after particularly vicious breakup as a means of humiliating the ex or just for own amusement"

By late 2008, the term was in use as the name of at least one website on an adult blog hosting service and in November of the same year, Details magazine published an article on revenge porn

It wasn't until three years later the media began to pay revenge porn serious attention, when, in December 2011, Facebook moved to prevent the website isanyoneup.com from providing links to the profiles of Facebook users alongside explicit photographs of them posted without their consent

Research by Jonathan Dent, an assistant editor for the Oxford English Dictionary