I looked it up...
The hand work is real... done by two people. Some effects are used to combine the work of four hands into the resulting image, but the hand work is real...
Client : YPO, Calcutta Chapter
Producer/Director: Priyanka Rungta, supported by Arka Bhattacharyya, Navsoft
Creative Agency : 100 Watts Design Studio
Branding, Art Direction & Copy : Kritika Malhotra
Production House: Arko Sen
Hand Shadows: Amar Sen, Sabhyasachi Sen
Published: December 2011
Here's the finished cut...
http://www.youtube.com/watch?v=H9LBHwlAeOU&feature=channel