A teenager detained for defrauding eBay customers netted £100,000 - more than double the previously estimated figure, a BBC Wales investigation has found.
Phillip Shortman said the crimes were simple to commit
In an exclusive interview for the Week In Week Out programme, Phillip Shortman claims his crime spree was simple to conduct and hugely profitable.
The Pontypool teenager described his crimes as "really easy".
Shortman, 18, was detained for 12 months at Cardiff Crown Court in May after admitting 21 counts of fraud.
The judge said he had shown "a sublime contempt for the law" by selling non-existent goods using the online auction site.
The teenager deceived more than 100 eBay customers over a 13-month period.
He spent the money on top of the range computer equipment, hi-fis and flat-screen televisions, as well as designer clothes and hiring stretch limousines.
In an interview, Shortman told Week In Week Out about the simplicity of his crimes.
"Very easy. Really easy. I was staying at hotels, posh hotels, I was travelling the UK," he said.
"I was going to all the theme parks in the UK. I was going abroad, travelled quite a bit of the world then... so it was really just all greed and it's just having the money there.
"I used to sell CDs - £17, £20 a disc, and one time I just couldn't be bothered to send the disc off.
"I waited a few weeks and nothing came of it. And it just sort of went on from there - selling discs and not sending the items... I had no e-mails, or phone calls or letter, so I just took it to a higher level."
One of Shortman's victims was Michael Davies, a retired telecoms engineer from Coventry.
He lost over £1,000 when trying to buy a set of mobile phones from Philip Shortman.
"I was new, someone new to e Bay, and rather naïve... and didn't really look for the obvious flags, like the fact that he had no feedback."
Mr Davies tried several times to contact Shortman - but to no avail.
"Each time I contacted him - his child had been taken ill or whatever. There was a series of excuses," he said.
But Shortman showed little sympathy for his victims. "I thought they were stupid, to actually put that much trust in somebody that they don't even know," he said.
"I would never do that myself. I would never send money to someone that I've never met."
eBay's UK head of trust and security, Garreth Griffith, apologised to the victims.
"We've learnt a lot from this case, certainly we have, and we have adjusted our technologies and processes accordingly, as we always do," he said.
eBay said it now has a thousand people working worldwide in order to combat fraud.
"I don't like it when things like this happen," said Mr Griffith.
"It's my role to prevent this. We learn a lot, we move on and we improve our systems. We are fundamentally, fundamentally committed to making it a safe place to trade."
The "Superhighway Robbery" documentary also looks at other growing forms of e-crime, including 'phishing attacks', where bogus e-mails encourage people to divulge their bank security details.
Week In Week Out's "Superhighway Robbery" is on BBC1 Wales at 2235BST on Tuesday, 7 June.