Empathy is considered essential to social bonding and emotional attachment, but it can also trigger "vicarious anxiety" for victims or others who are genuinely distressed. Some psychologists have called empathy a "risky strength" because it predisposes us to experience others’ happiness but also their pain. The successful tuning evident in both Facebook experiments is the result of the effective exploitation of the natural empathy present in its population of users.

Shoshana Zuboff, The Age of Surveillance Cap…, loc. 946