A deep analysis on social bots, fake news, hate speech and filter bubbles on Twitter. This is questions the existence, as well as quality of studies about, the co-called "social bots" (which turned out to either have no influence, or to be real people with "too much" free time):

Michael Kreil: Social Bots, Fake News und Filterblasen

https://media.ccc.de/v/34c3-9268-social_bots_fake_news_und_f...

(German talk, but the video contains an audio track with a good English translation.)