For what it's worth, Snopes did an article about these brain-wave trackers: https://www.snopes.com/news/2018/05/03/activists-skeptical-concerned-reports-emotion

For what it's worth, Snopes did an article about these brain-wave trackers: https://www.snopes.com/news/2018/05/03/activists-skeptical-concerned-reports-emotion-monitoring/ https://www.snopes.com/news/2018/05/03/activists-skeptical-c... tl;dr is that they kinda work, but not nearly as effective as advertised. It also raises the point that even if it didn't work, all you need to suppress people is for them to believe that it's working.