Elizabeth Dwoskin And Hamza Shaban The Washington Post

In a reversal, Facebook chief operating officer Sheryl Sandberg admitted Wednesday that she knew the company had hired Definers, the Republican-affiliated consultancy that conducted opposition research into Facebook's critics.

In a reversal, Facebook chief operating officer Sheryl Sandberg admitted Wednesday that she knew the company had hired Definers, the Republican-affiliated consultancy that conducted opposition research into Facebook's critics.