Yahoo coming under fire for its disclosure, just last week, that data related to 500 million user accounts was hacked two years ago.

FOX's Jon Decker reports: 

Six Democratic Senators have asked Yahoo CEO Marissa Mayer for more information into the company's investigation of the hack, saying they were "disturbed", the two-year-old cyber attack was announced only last week.

Calling the delay in disclosing the hack "unacceptable", the Senators in a joint letter expressed concern that the data of 500-million Americans may have been compromised for two years.

Experts say the hack could have a wide-ranging impact on other websites.

At the White House, Jon Decker, FOX News.