Using fb to advertise for Obama, Trump, etc, is ok
However that's not what has been done, but the a) use of shills and fake personas to pump up opinion b) creation of fake "grassroots movements" and "news articles" with a divisive purpose
https://thinkprogress.org/russia-facebook-pages-sophisticate...
https://www.reddit.com/r/RussiaLago/comments/7y6ola/there_ha...