This is amazing and almost unbelievable. How do you get your all white outfit together, and bring what you have to bring, arrive in public transportation in just one hour? I assume some is planned ahead.
http://www.dailymail.co.uk/news/article-2341282/All-white-night-Thousands-revellers-secret-supper-shadow-Eiffel-Tower.html
And this closer to home. Explains a bit more.
http://heatherinsf.wordpress.com/2012/12/31/diner-en-blanc-san-francisco/