You might be interested in the 15th episode (of the 4th series) of Person of Interest, "Q & A" (Aired at February 17, 2015), in which depressed and addicted people were targeted with special adds to drive profit up. I won't spoil the whole episode, but it certainly made me think about our implicit, almost tacit trust in search engines, social media sites, and other services we don't fully understand (as users, because we don't have access to the source or data), but which we use daily. I can only imagine our dependence on these services to grow in the future, while our understanding of these complex systems does not grow at the same rate (or at all).