"The batch of more than 3,000 Russian-bought ads that Facebook is preparing to turn over to Congress shows a deep understanding of social divides in American society, with some ads promoting African American rights groups, including Black Lives Matter, and others suggesting that these same groups pose a rising political threat, say people familiar with the covert influence campaign. The Russian campaign — taking advantage of Facebook’s ability to send contrary messages to different groups of users based on their political and demographic characteristics — also sought to sow discord among religious groups. Other ads highlighted support for Democrat Hillary Clinton among Muslim women."