https://www.cnet.com/news/facebook-board-defends-sheryl-sandbergs-ask-for-research-on-george-soros/

"As is to be expected following an attack from such a well-known and widely respected figure, Facebook staff immediately initiated research to attempt to understand the motivations driving the criticism, financial or otherwise," the letter says. "To be clear, Ms. Sandberg's question was entirely appropriate given her role as COO. When a well-known and outspoken investor attacks your company publicly, it is fair and appropriate to do this level of diligence."

Facebook General Council Colin Stretch sent the letter Wednesday to Patrick Gaspard, president of Soros' Open Society Foundations, on behalf of the Facebook board. The Wall Street Journal earlier reported news of the letter.