Reverse engineering addictive products

> Facebook has implemented an algorithm that shows me new content based on what I have interacted with in the past... but Facebook could do some really egregious things before people would stop using it.

Did the author miss Facebook experimenting on users with the news feed by putting 'harder' new items to see if they could alter users' emotional state?

http://www.wsj.com/articles/furor-erupts-over-facebook-exper...