Australian men are sharing pictures of women, in some cases without consent, on Craigslist.
Some of the advertisements offered pictures of ex-partners as well as current girlfriends or wives.
One Melbourne man posted a picture of a woman he had presumably slept with and asked to "swap pics of young sluts".
Another Melbourne man wanted to "show off pics" of his wife in exchange for pictures of other men's wives.
"Its hot knowing they are unaware and being seen in such a way," the man wrote.
In 2014 it became a criminal offence to maliciously distribute intimate images in Victoria without the subject’s consent. Offenders can be jailed for up to two years for distributing images and for up to a year for threatening to distribute images.
One Sydney man posted a picture of a sleeping woman who he "did" the previous week and offered to trade more pictures of his previous sexual partners in return for other people's photos of their sexual partners.
In 2016, two weeks after revelations teenage boys were swapping graphic sexual images of girls from more than 70 Australian schools without consent, New South Wales moved to criminalise revenge porn.
In August this year, the state added a new offence – to distribute "intimate images" or intentionally record someone without consent, or threaten to share said images – to its criminal laws. It carries a maximum penalty of three years in jail and an $11,000 fine.
There were many advertisements in which men were selling their partner's used underwear.
A Gold Coast man posted an advertisement on Craigslist in which he offered to send pictures of his wife's underwear and wrote that he thought it was "kinky" that other men were seeing them "without her knowing".
A Brisbane man asked for "cash" for the "many" photos and videos he had of his ex-girlfriend.
Queensland currently has laws where if someone makes a demand with intent to gain a benefit or cause harm they can be imprisoned for 14 years, but there are no specific offences relating to revenge porn. However, premier Annastacia Palaszczuk has vowed to make revenge porn a criminal offence.
One Perth man offered footage of his ex-wife in exchange for similar content, and another was "looking to swap pics of women we have fucked" via messaging service Kik.
Unlike Victoria, South Australia and NSW, which criminalise revenge porn as a standalone offence, Western Australia created restraining orders that stop people sharing intimate images, so its revenge porn laws are limited to domestic relationships. The maximum sentence is two years.
Another Perth man had uploaded 11 pictures of his wife naked or in lingerie – which may have been done with her consent – to accompany his advertisement, in which he requested similar pictures of other men's partners.
A Canberra man was offering six videos and pictures of his girlfriend in return for nudes or videos of other girls in the same city.
The ACT has criminalised the non-consensual distribution of intimate images and the maximum sentence is five years if the image is of someone aged under 16 years of age; otherwise, the maximum sentence is three years.
BuzzFeed News responded to more than 40 advertisements, asking whether the woman involved knew her photos had been shared (in the advertisement) or would be shared with strangers who responded.
Only three advertisers replied. One said his wife knew but wasn't "participating".
The second said: "No she doesn't [know]." and attached six naked pictures of a woman he said was his wife.
The third, a Hobart man, also confirmed his wife had no idea.
Tasmania has no specific laws around sharing intimate images, but the state's opposition Labor Party has a proposal it planned to table by the end of last year. It should be put forward this year.
Some advertisements have been deleted since BuzzFeed News responded to them.
Revenge porn no longer refers solely to the illegal distribution of intimate photos taken over the course of a relationship, but to any unauthorised public release of an intimate image.
One-in-five Australian adults who took part in a survey say they have had images or videos of a nude or sexual nature taken without their consent; 11% say these images or videos were shared; and 9% said they received threats that the images would be shared, a study from Monash University found in May. The 4,200 respondents were aged from 16 to 49.
The eSafety Commissioner's office has identified that the "non-consensual sharing of private sexual images can be a form of family violence or sexual abuse".
There are no specific federal laws regarding revenge porn, but if an Australian is using a carriage service to cause menace, harass, or offend, the maximum penalty is three years in prison.
Here is more information about the legal status of revenge porn in your state or territory.
Concerned Queenslander Jerry Grey contacted BuzzFeed News last week after he responded to a Craigslist advertisement in which a 25-year-old man was selling his 19-year-old girlfriend's panties.
"The ad was red-flagged for me as pure revenge porn from an ex-partner," Grey told BuzzFeed News.
"I answered the ad pretending to be an interested person to confirm my gut feeling."
The man sent Grey pictures of the woman in her underwear and when Grey asked if she knew he had done so, the man said no.
Grey, a web engineer, said revenge porn was a "pet peeve" of his.
"It is something I’ve been trying to get politicians and law enforcement to pay attention to and to act on, especially with it running rampant across the back pages of the internet."
BuzzFeed News has contacted Craigslist for comment.
Australia's eSafety Commissioner Julie Inman Grant said there was help available to anyone who has been a victim of image-based abuse.
She encouraged people to collect evidence, report the image to the social media service or website, report to the eSafety Commissioner, engage help from police, seek legal assistance and get support to ensure your mental health and physical wellbeing.
"Sadly, our latest research tells us that a growing number of Australians are experiencing image-based abuse, with as many as one in five women aged 18 to 45 victimised by this insidious behaviour," Inman Grant told BuzzFeed News.
"At our online portal, you can find practical information and advice about what to do if you or someone you know has been the victim of image-based abuse."