You may have heard that Facebook manipulated the content of user's New Feeds during January of 2012 so that some users saw more positive posts than others, which other Facebook users saw more negative posts. \xa0How did this affect these users? \xa0Did those who say negative posts become more negative and vice versa? \xa0The answer is that the research indicates that some of them - though a very, very few of them - did subsequently write posts that were similar to the ones that saw on their News Feed. \xa0How big of an effect is this? \xa0Is it unethical? \xa0Does agreeing to Facebook's Terms of Use constitute "informed consent". \xa0I examine these questions in this episode of The Psych Files.