University student Sophie Meehan was enjoying a family trip to the theatre in London when pictures of a stranger's genitals popped up on her mobile phone. The 20-year-old was about to board a train to return home to Kent in southeast England last year when an AirDrop file appeared on her phone so she opened the file and was aghast.
Meehan, who closed the file to immediately be sent it several times more, said she felt totally confused on receiving the unsolicited image and at becoming another victim of cyber-flashing, a technology-based crime currently in a legal void.
"It was just shocking ... also a bit uncomfortable and a bit gross, but mainly just shocking," she told the Thomson Reuters Foundation in a phone interview, adding the man she believed sent the image was close by and watching as she opened it.
Meehan said it was only when she researched online that she discovered, like many women, she had fallen prey to a growing form of image-based sexual abuse called cyber-flashing - when a man sends a photo of his penis via a digital device.
In Britain, more than 40% of millennial women have been sent an unsolicited photo of a man's private parts, according to a YouGov poll in 2017, while just over half of U.S. millennial women have received a graphic image, according to a separate YouGov poll in the same year.
But despite this prevalence, only a handful of places - including Singapore, the U.S. state of Texas and Scotland - have introduced specific legislation to deal with cyber-flashing, with women's rights campaigners pushing to fill this legal hole.
Most countries have existing laws that only partially cover this sort of activity, normally related to sexual harassment or communication, Clare McGlynn, a professor of law at Britain's Durham University, told the Thomson Reuters Foundation.
"It's a real hotch potch of different provisions [in different countries] and it's not clear," she said.
In late 2018, a cross-party group of British parliamentarians recommended that the government introduce a new image-based sexual abuse law to criminalise cyber-flashing. The government vowed to act in March last year, but later rejected the recommendations.
Legal reform is urgently required globally to make it clearer that cyber-flashing is punishable by law which would deter those responsible, said McGlynn.
Criminal legal reform would send "a clear message that it's unacceptable, that recognises that this is harmful and that someone can be punished for it", she added.
Legal changes are needed to keep pace with the way men are using technology to abuse women, said Niki Kandirikirira, programmes director at women's rights group Equality Now.
"Current laws are not keeping up with how technology is facilitating sexual harassment and abuse - old crimes are being perpetrated in new ways," she said.
UNSAFE IN PUBLIC
Cyber-flashing can be "deeply distressing and unnerving for recipients and sends a toxic message to women and girls that they are not safe in public space", she added.
The anonymous nature of digital devices makes men think they can get away with the activity, she pointed out.
"Being able to intentionally expose their genitals to a stranger using digital means significantly reducing the risk of being caught," she said.
Last week a new Twitter plugin called Safe DM launched, designed at blocking and deleting unsolicited graphic photos from people's private messages on the social media platform.
Research published last year by Denmark's Aarhus University found girls find unsolicited so-called "dick pics" intrusive and often regard them as misguided attempts at flirting. Men who engage in the activity, however, tended to view it as a means of showing off, complimenting, hooking-up, or even receiving nude photos from girls in return, the research found.
McGlynn said there were signs that women were becoming more aware of cyber-flashing and speaking up about it, rather than just deleting the text and staying quiet. "Raising awareness is as much about - particularly with younger women - being able to understand this is wrong and that they don't have to put up with it," she said.