The mastermind behind what the government says is one of the largest cryptocurrency Ponzi schemes prosecuted in the US has been sentenced to 15 years in prison. While crypto scams have been getting increasingly common, Swedish citizen Roger Nils-Jonas Karlsson defrauded thousands of victims and stole tens of millions of dollars over a period that lasted almost a decade. He pleaded guilty to securities and wire fraud, as well as money laundering charges on March 4th.

According to the Department of Justice, Karlsson ran his fraudulent investment scheme from 2011 until he was arrested in Thailand in 2019. He targeted financially insecure individuals, such as seniors, persuading them to use cryptocurrency to purchase shares in a business he called “Eastern Metal Securities.” Based on information from court documents, he promised victims huge payouts tied to the price of gold, but the money they handed over wasn’t invested at all. It was moved to Karlsson’s personal bank accounts instead and used to purchase expensive homes and even resorts in Thailand.

To keep his scheme running for almost a decade, he’d rebrand and would show victims account statements in an effort to convince them that their funds are secure. Karlsson would then give them various excuses for payout delays and even falsely claimed to be working with the Securities and Exchange Commission. During the sentencing, US District Judge Charles R. Breyer ordered his Thai resorts and accounts to be forfeited. He was also ordered to pay his victims in the amount of $16,263,820.

Acting US Attorney Stephanie Hinds of the Northern District of California said:

“The investigation into Roger Karlsson’s fraud uncovered a frighteningly callous scheme that lasted more than a decade during which Karlsson targeted thousands of victims, including financially vulnerable seniors, to callously rob them of their assets and all to fuel an extravagant lifestyle surrounded by luxury condominiums and lavish international vacations. The court’s decision to order a 180-month prison term reflects the fact that Karlsson’s cryptocurrency Ponzi scheme is one of the largest to be sentenced to date and ensures that Karlsson now will have plenty of time to think about the harm he has caused to his victims.”