According to Wikipedia, the largest pillow fight flash mob was the Worldwide Pillow Fight Day (or International Pillow Fight Day) that took place on March 22, 2008. Over 25 cities around the globe participated in the first "international flash mob", which was the world's largest flash mob to date.
Below are some interesting analog photos of pillow fights in the past few years from various cities around the world.
|Vancouver Pillow Fight (8 of 8) by falln_angel|
|Pillow Fight 2008 by JoeBake|
|Pillow Fight 2009 by djspyhunter|
|Toronto Pillow Fight 2009 (from film) by jasonainsworth75|
|celebrità by elnuego|
|Pillow Fight (50) - 04Apr09, Paris (France) by philippe leroyer|
|International Pillow Fight Day 2010 by meihui_lee|
|by Gebhart de Koekkoek|
|Pillowfight by VLBPhotography|
|pillowfight @ london - trafalgar square by Thom_Mi|
|Pillow fight. Damsquare, Amsterdam by Pim Geerts|
(via Flickr Blog)