When infidelity dating site Ashley Madison was hacked, the details of 33 million user accounts were published on the web.
The BBC has spoken to two women, one whose fiance used the site and one who used it herself.
Neither wanted to be identified, but their stories give some hint of just how dramatic and wide-reaching the impact of the hack has been.
The first only wanted to be named as "Maria". She says she used an online tool to search for her fiance's email address in the dumped data.
"I really didn't think I would find anything on anybody," she comments.
She wanted to check, though, because one of her own email accounts had been compromised recently.
When she entered her fiance's address as well, the database not only confirmed it was there but it spat back a postcode, city and birthdate. All were accurate.
"These things logged your IP [Internet Protocol] address, they logged your provider, they logged everything and not only that, it was your physical description," she explained to the BBC. "It matched his to a T."
Maria quickly confronted her fiance.
"He denied and denied and denied at first and then he acquiesced and confessed what he did.
"Yes, (he said) he did have multiple affairs, yes. It just... it came out," she says.
Her fiance said that he couldn't explain fully why he did what he did and that Maria meant more to him than the women he had met on Ashley Madison. But the conversation didn't last long.
Maria packed a week's worth of clothes and left to stay with a friend. The wedding they had been planning is cancelled.
She has since booked a sexual health check, she says, and tried to distance herself as much as possible from her fiance. The whole experience has been "shattering", she adds.
"It's one thing if you come forward and say I'm not satisfied or I'm not happy or I'm finding it hard to remain faithful - as long as you're open," she says.
"It's just completely unfair to waste years of a person's life with duplicity."
Ashley Madison: In numbers
User accounts leaked
Canadian dollars reward for information on hackers
300 gigabytes Data reported stolen by hackers
197,000+ Emails leaked from chief exec's work account
$115m Sales reported by parent company Avid Life Media in 2014
13 years ago Infidelity site founded
You don't have to look far online to find examples of internet users who seem to be personally affected by the hacking of Ashley Madison. Various forums are full of threads from those who believe their "SO" (significant other) was on the site.
But users of the dating site are also turning to the web for help.
One woman who used Ashley Madison, but who did not want to be named, has also spoken to the BBC. For the purposes of this article, we will refer to her as "Amy".
She has been married to her husband for 10 years.
But recently she became interested in the idea of having an affair. She had heard advertisements for Ashley Madison on local radio, so a year ago she signed up and began looking for a man with whom to have a relationship.
However, she says she never messaged anyone and soon closed down the account. But six months ago she created another and this time she wanted to address questions she had about her sexuality by contacting other women.
This time she did find someone to talk to. They emailed one another, she says, for several weeks.
"She was close to where I live and we seemed to hit it off," says Amy.
"Her story seemed so much similar to mine. She was someone who had been married for a while [and] she had always been curious about that side of herself."
Amy says the woman she corresponded with told her she thought she was attractive, which made Amy feel flattered.
They were due to to meet, but at the last moment Amy called it off. She says she became fearful and began to feel that her marriage was something she didn't want to jeopardise.
"Using it kind of made me realise that there were other things that I need to look at," she explains.
"It's scary when you have this person that you love so much and you think about hurting them."
Married and curious
Amy says that so far she hasn't told anyone who knows her about what happened, but she's now worried that her husband might find out that she used the site.
She has distracted herself with work for now, but comments that she feels stressed and that the episode has affected her sleep.
Ashley Madison offered users a $19 (£12) "Full Delete" service, which Amy says she used. She checked an online tool to search for her email address in the leaked database and was surprised to find it there, along with other information such as her postcode, gender and the name associated with her credit card.
It's not clear what has happened in this case, but it's possible that the database was downloaded by hackers before the date on which Amy paid for her information to be removed.
Either way, she thinks there is now a possibility she'll be found out.
"If my husband were to come home from work today and say someone found my information I would be open and honest with him about it," she says.
"It's really made me think about my behaviour and why I did what I did - and to cherish what I have."
For now, though, Amy just hopes her husband won't find out.