Washington weighs response to Sony hack; options limited

By David Brunnstrom and Piya Sinha-Roy WASHINGTON/LOS ANGELES, (Reuters) - The U.S. government on Thursday said it was weighing the proportional response to the sophisticated perpetrator of a cyberattack that crippled Sony Pictures, exposed its executives and led to the cancellation of the film "The Interview." Spokesman Josh Earnest said the White House is not in a position to confirm that North Korea is responsible for the hack at Sony, after a U.S. official said Wednesday that Washi