The study, which covers tweets from January 1st, 2016 through September 30th, 2017, noted that many of the accounts posed as activists on both major sides of contentious issues. As on Facebook, Russia's "troll team" (the IRA) was trying to exploit social divisions. It's not known how many of the accounts were created explicitly for propaganda purposes versus being hijacked, but at least some of them have shut down (whether through Twitter bans or otherwise).
The findings not only show how pervasive the Russian manipulation campaign has been both during and after the US presidential election, but illustrate how effective the messages could be. Even outlets that are famous for their thorough fact-checking inadvertently magnified the Russian government's bogus messages -- were they going to trace the origins of every tweet? And in at least some cases, it's prompting a change of strategy. The Post, for example, is both correcting past stories and will "assess [its] policy" for citing tweets in articles. However tempting it is to blame the social networks themselves for turning a blind eye to Russian propaganda, those who shared that propaganda also bear some responsibility.