Some people are like that, if it's possible, it's probably happening.
 As for those people manipulating, there's all types of motivations moving people, there are so many players in the game, we have to separate them by their tempers, hatreds, loyalties. A perfect game is improbable, even if we closed every loop hole, there would still be aspects we simply must trust are operating honestly, but what can be done is educating people to notice... and at the least take part in their own narrative upon noticing manipulation; help the attacker and make money? or counter it and make money?

 That is the miracle of the Blockchain, it changes all the rules, we are seeing history unfold, transcribed in all it's imperfection onto a permanent record. Whatever version of history we subscribe to, all those nuances will be caught and recorded for posterity.