Yahoo today (Jan. 30) reported a coordinated effort to break into an undisclosed number of Yahoo Mail accounts, and said it was resetting the passwords on all affected accounts. The list of usernames and passwords that were used to execute the attack was likely collected from a third-party database compromise, Yahoos Jay Rossiter, senior vice president of platforms and personalization products, wrote on Yahoos official Tumblr page. We have no evidence that they were obtained directly from Yahoos systems.