had many accounts hacked into on Saturday, starting with his Apple mail account, and working their way through Gmail, Twitter and more. In his summary, which is a must read if you care about keeping your data secure, he references that "2 factor authentication" would have kept his Google account safe, but not prevented the initial hack, done through social engineering via Apple support.
I cannot endorse two step verification any more deeply. I once had my Apple account compromised, and foolishly used the same password for Amazon and other sites. Resetting everything and getting things resolved was a pain, and I was lucky not to have been embarrassed or had my credit cards impacted. Not everyone will be, so take care of your data.
1. Read more on two step verification: http://goo.gl/8GQrj
2. My post on when my Mac account got hacked: http://goo.gl/3bjG6