'How I caught my online scammer – and Facebooked his mum'
A cybersecurity researcher living in Austria who was scammed out of $500 (£375) says his money was returned after he tracked down the scammer's family and contacted them on Facebook.
Christian Haschek's blog post about how he caught the thief has been viewed more than 100,000 times in five days.
The scammer was using the same usernames elsewhere on the net, which made him easier to track down.
Mr Haschek says he has "mixed feelings" about his victory.
"On the one hand, this is someone who stole $500 from me and deleted all the accounts that I used to get back to him, he never answered my messages," he told the BBC.
"I found out he had tried to scam loads of people and always with gift cards."
However, the con artist appeared remorseful and said he was afraid. He seemed to come from a poor background and said he was a full-time student.
"He is also just a kid who took a wrong turn," added Mr Haschek, who has not reported the man to the authorities.
Mr Haschek advertised some Apple gift vouchers, which he had won in a competition, on various online message boards as he was unable to use them himself.
The fake buyer who duped him agreed to pay for the vouchers in Bitcoin.
He had decided to accept payment in the digital currency as he thought it would be less of an incentive for a scammer.
The buyer told him he would pay once he had the gift voucher codes as proof that they were genuine.
"The problem for the buyer is you never know if the cards are still valid after you pay - even if I had sold them I could have used the cards straight afterwards," he said.
"He said I could be a scammer and he wasn't going to pay me until he got them… I could see that."
Mr Haschek added that he had been unsuccessfully trying to sell the vouchers for four years.
However, once the swindler had received the digital codes he used the vouchers straightaway, while trying to claim that the physical cards themselves had not been delivered.
"I started sweating a lot because I had trusted him - I gave him the benefit of the doubt," Mr Haschek continued.
"I realised he was a scammer when he started to delete his accounts."
However, Mr Haschek said it took him four days to find his culprit.
Message to mum
He discovered the scammer was using the same usernames on other sites, including recruitment websites, and was able to track down additional information about him, including the names of his friends and family.
The fraudster stopped replying to his messages so eventually he sent a message to his mother and brother on Facebook explaining what he had done.
"Ten minutes after Facebook said his brother read the message, the scammer was contacting me on Reddit again," Mr Haschek said.
Mr Haschek added that the con artist sent a new gift card and apologised, saying he had acted because he had no money.
Mr Haschek's advice to online traders is to use a traditional escrow service - where both the money and goods are exchanged via a third party.
"I took the risk knowingly - but paying before you get something is always risky," he said.