On Monday, a 4chan user started this thread, asking the other members of the community what they thought he should do in his sister's room while she was at work.
One user suggested putting on his sister's underwear and posting a photo. The original poster of the thread then published a photo of a man wearing what appears to be women's underwear next to a note with the date written on it.
Then the original poster uploaded a photo of the underwear and a bra. A few minutes later, an anonymous user posted a photo they claimed was of the original poster's sister.
Users started celebrating the fact that they had unmasked the girl they believed owned the underwear from the first photo. Then they started matching up photos from that girl's Twitter account with details from the original photo.
They started locating her other social media accounts as well.
Then another user tweeted the original photo at the girl's Twitter account.
One user joked that they hoped the original poster would kill himself over the whole thing.
The whole thread was archived on Reddit's r/4chan and by Tuesday morning it was on the front page of Reddit.
The account 4chan named as the sister of the original poster started getting flooded with harassment, as well as copies of the original underwear photo.
Many were celebrating the fact they found her, while others just tweeted obscene stuff at her.
BuzzFeed News started following the account while the story was trending on Reddit and reached out for comment.
Later on Tuesday, the account was hacked and taken over by someone who saw the story on 4chan.
They started filling the account with random hate speech.
The person who hacked the account, who requested to be called "Lucifer The Redeemer," then reached out to BuzzFeed News via direct message.
The person said they have had no contact with the owner of the Twitter account and only hacked into it because they could.
When asked why, they said they did it for all the virgins and neckbeards on 4chan.
As of press time, it appears that a hacker is still in control of the account and is attempting to get people to send them bitcoins.
BuzzFeed News has reached out to Twitter for comment.
Ryan Broderick is a reporter for BuzzFeed News and is based in London.