Michelle Obama, Ashton Kutcher and Beyonce have been warned to safeguard their bank accounts.
A growing list of celebrities, which also includes Kim Kardashian, Jay-Z, Donald Trump, Mel Gibson, Hulk Hogan, Britney Spears and Al Gore, have been targeted by hackers, who obtained their private account details, home addresses and social security numbers, and anonymously posted them online in a major US security breach.