Niall McNamee was scrolling through his phone on the London Underground when a thief on the platform snatched it from his hand just as the doors closed.
Two days later the 30-year-old discovered his bank accounts had been drained by about £21,000 - including a £7,000 loan taken out in his name.
"It used to be people stole a phone so they could sell on a phone," he told the BBC. "Now it seems they are stealing phones so they can get into all of your data and take money."
Niall is not alone - across Britain, reports of theft and robberies on trains and at stations shot up 58% from 2018 to 2023, according to British Transport Police (BTP) data.
The force, which polices the rail and underground networks in England, Wales and Scotland, has warned the month of December had the highest number of thefts and robbery reports in recent years.
Superintendent John Loveless said during the autumn and winter months offenders operated under the "cover of darkness" to target people. "The nights drawing in earlier, it gives people an opportunity... for offending," he added.