Flash mob, 快閃族

Flash mob forms in downtown Pottstown to support local business
http://www.pottsmerc.com/article/MP/20170216/BUSINESS/170219816
台北快閃族 愛川こずえ Flash mob in Taipei - YouTube
https://www.youtube.com/watch?v=nz4osVdmfnk
【中視新聞1000126】巴黎東站 快閃族表演旅客驚喜 - YouTube
https://www.youtube.com/watch?v=PD1MxLDs-BU

Flash mob - Wikipedia

快閃族