LoveBomb (by Rebecca et al. 2001)
The LoveBomb - a mobile and persuasive device that allows people to anonymously communicate feelings of love (happiness) and sadness. The device contains a radio transceiver that the user can employ to send out shock waves of love, affecting people in the proximity carrying a LoveBomb device. The device also lets its users cry for compassion, quietly signaling to others that they are sad. The LoveBomb is intended to encourage people to express themselves emotionally when situated amongst strangers in public spaces.
Source: Hansson, R., Akog, T. The LoveBomb: Encouraging the Communication of Emotions in Public Spaces. In Extended abstracts on Human Factors in Computing Systems, CHI '01. 433-434