https://www.washingtonpost.com/business/technology/russian-operatives-used-facebook-ads-to-exploit-divisions-over-black-political-activism-and-muslims/2017/09/25/4a011242-a21b-11e7-ade1-76d061d56efa_story.html?
"...Investigators at Facebook discovered the Russian ads in recent weeks, the company has said, after months of trying in vain to trace disinformation efforts to Russia. The company said it has identified at least $100,000 in ads purchased through 470 phony Facebook pages and accounts. Facebook said this spending represented a tiny fraction of the political advertising on the platform during the 2016 campaign.
The divisive themes seized on by Russian operatives were similar to those that Trump and his supporters pushed on social media and on right-wing websites during the campaign. U.S. investigators are now trying to figure out whether Russian operators and members of Trump’s team coordinated in any way..."