Turns out the identity of JK Rowling as the true author of a pseudonymous detective book was revealed by a partner at Russells, her law firm. He told his wife's friend who went public. What would happen in the US? She has no monetary damage, quite the opposite.
According to the Guardian:
The company said in a statement: "We, Russells Solicitors, apologise unreservedly for the disclosure caused by one of our partners, Chris Gossage, in revealing to his wife's best friend, Judith Callegari, during a private conversation that the true identity of Robert Galbraith was in fact JK Rowling.
"Whilst accepting his own culpability, the disclosure was made in confidence to someone he trusted implicitly. On becoming aware of the circumstances, we immediately notified JK Rowling's agent. We can confirm that this leak was not part of any marketing plan and that neither JK Rowling, her agent nor publishers were in any way involved."