The US Department of Justice is investigating a data breach at Coinbase, where hackers accessed user information through compromised customer support channels. The incident resulted in potential financial losses estimated at $400 million and highlights vulnerabilities in social engineering tactics targeting customer service. Coinbase CEO Brian Armstrong and Chief Legal Officer Paul Grewal are collaborating with authorities to address the breach, promising prosecution of those responsible and adjustments to operational security practices. The investigation is also raising regulatory concerns as personal data leaks heighten risks for affected individuals and fuel calls for stricter oversight in the cryptocurrency industry.