Machiavellian. You are also overlooking pump and dump Twitter accounts which sway stock by micro-increments, this tactic becoming more of an art than a science these days (Twitter clamped down on those accounts in recent years). Also see http://www.huffingtonpost.com/2013/03/11/twitter-hoax_n_2850...
I think that too many are calling this magic, or liking it to paranormal, but 50 years from now we will look back and it will be no more normal than the law of gravity, or other physical 'givens' of the universe