There's something uniquely agonising about having your cryptocurrency stolen. All transactions are recorded on a digital ledger, known as a blockchain, so even if someone takes your money and puts it in their own crypto wallet, it is still visible online.
"You can see your money there on the public blockchain, but there's nothing you can do to get it back," says Helen, who lost around $315,000 (£250,000) to thieves.
She likens it to watching a burglar pile up your prized possessions on the other side of an impassable chasm.
For seven years Helen and her husband Richard (not his real name), both UK residents, had been buying and stacking up crypto coins called Cardano.
They liked the idea of investing in a digital asset that had the potential to rise dramatically in value, unlike funds saved in more conventional ways. They knew it was riskier, but they were careful to keep their digital keys safe.
But somehow hackers got into their cloud storage account, where they kept information about their crypto wallets and how to access them.
In February 2024, after a small test transfer, the criminals sent all the couple's coins to their own digital wallets in a swift and silent attack.
The couple then watched for months as their money was moved from one wallet to another, powerless to do anything. (The inherent contradiction with crypto currency is that all transactions are publicly trackable but users can be publicly untraceable if they choose.)
Helen and Richard are not wealthy. She is a personal assistant, he is a composer, and they had high hopes for their Cardano investments.
"We'd been buying these coins for so long... We used every scrap of money we could find to buy more," says Richard. "Aside from my parents' deaths, this theft is the worst thing to happen to me."
Ever since, Helen has been on a mission to recover their money. She obtained detailed reports from various police forces and the Cardano developers. Now, even though she has the wallet address of the criminals, there is nothing anyone can do to unmask them.
Their plan is to save up enough to engage private investigators to try to trace the hackers.
"It leaves you with a feeling of helplessness," she says, "but I am going to keep trying."
A survey carried out for the Financial Conduct Authority (FCA) in August 2024, suggested that approximately 12% of British adults owned crypto-assets - equivalent to about seven million people.
Hacking, scamming or coercing of individuals accounted for an estimated 20% of all crypto value stolen - estimated at $713m (£532m).
But the company adds that the number could be far higher as not all victims will choose to report thefts publicly. When this happens, you could be left on your own.
Many thefts or scams in traditional finance are covered by banks or card companies. In the UK you can complain to the financial ombudsman service and may be compensated by the financial services compensation scheme.
"Crypto remains largely unregulated in the UK and high-risk," says the FCA. "If something goes wrong, it is unlikely you will be protected so you should be prepared to lose all your money."
A stark reminder of this comes if you search online for "Binance account hacked" - Binance is the world's largest crypto exchange with a reported 1.4m UK users - but the page on its website offering advice to victims of theft is blocked in the UK.
The company has not been accepting new UK clients since 2023, because it is not authorised to operate by the FCA. Yet criminals don't care where victims are, and people are being targeted all over the world indiscriminately.
Chainalysis has described these attacks on individuals as the "under-documented frontier for crypto crime".
They put the volume of crimes down to the numbers of people entering the crypto world as investors as the value of coins has risen and argue that improved security practices at major services could have pushed "attackers toward individuals perceived as easier targets".
Then there is the fact that the more crypto you hold and the more public you are about it, the more likely you are to be targeted - small time holders, (or hodlers, as the community calls them) are far less likely to be affected.
As for the thieves, they could be anywhere.
In October blockchain researchers from Elliptic, a crypto analysis company, warned that North Korean state-sponsored hackers are increasingly targeting wealthy cryptocurrency owners. There are plenty of young scammers and hackers from other countries too.
In December in the US, 22-year-old Evan Tangeman pleaded guilty to being part of a group of crypto thieves calling themselves the Social Engineering Enterprise, who are accused of stealing more than $260m (£194m) between October 2023 and May 2025.
Prosecutors allege they targeted the crypto-rich using hacked databases, tricking victims into thinking they were cryptocurrency exchanges, and persuading them to transfer coins.
Members of the gang, who were all young men mostly in the US, are said to have spent the stolen coins on private jets, expensive cars and luxury handbags that they would give away at nightclubs.
