The Facebook Emotional Contagion Experiment refers to a controversial 2012 study where the social media giant manipulated the news feeds of nearly 700,000 users to test the transfer of emotions. By filtering positive or negative posts, researchers aimed to see if users would mirror those emotions in their own status updates without their explicit consent. The study, published in 2014, sparked a massive ethical debate regarding the power of big tech over human psychology and the lack of informed consent. In meme culture, this event is frequently cited to poke fun at Facebook’s perceived 'mad scientist' approach to user data or to explain sudden shifts in online mood. It serves as a recurring trope for highlighting corporate overreach, algorithmic control, and the often-eerie nature of digital social engineering.