The New York Times, February 12, 2010 by Miguel Helft
http://www.nytimes.com/2010/02/13/technology/internet/13google.html
“You want to have a simple rollback mechanism, so once things are not what you expected them to be, you can get out quickly and not have to play a game of Whack-a-Mole,” said Deirdre Mulligan, a privacy expert and assistant professor at the School of Information at the University of California, Berkeley.