"For a period of time in 2013, the Times reported this year, a full half of YouTube traffic was "bots masquerading as people," a portion so high that employees feared an inflection point after which YouTube's systems for detecting fraudulent traffic would begin to regard bot traffic as real and human traffic as fake. They called this hypothetical event "the Inversion."

http://nymag.com/intelligencer/2018/12/how-much-of-the-internet-is-fake.html