The CEO of Starling, a digital bank backed by Goldman Sachs, has ratcheted up his anti-crypto rhetoric, claiming digital currencies are a threat to payment system security. “It is very dangerous,” Anne Boden, who founded Starling in 2014, warned Tuesday at the Money 20/20 fintech conference in Amsterdam. Based in the United Kingdom, Starling provides fee-free checking accounts and loans via an app. Goldman Sachs and Fidelity Investments are among the firm’s investors. It was last valued privately at £2.5 billion ($3.1 billion). Boden said, “This is a threat to the safety of our payment schemes worldwide.” Major Payment Companies are Adopting Cryptocurrencies Major payment companies are adopting cryptocurrencies: credit card companies Mastercard and Visa, for example, have opened their networks to digital assets, while PayPal now allows customers to trade bitcoin and other cryptocurrencies. Regulators are concerned that the banking system will become further entangled with the unpredictable realm of cryptocurrency. In the last month, the value of all cryptocurrencies has dropped by almost $400 billion, as investors were startled by the collapse of TerraUSD. This popular so-called stablecoin was always supposed to be worth $1. Boden isn’t the first person to warn about the perils of the crypto world. She has previously raised concerns about the potential of customers becoming victims of fraud as a result of cryptocurrency invest...