A reporter at Wired had his digital life destroyed (including personal mac wiped) by social engineering, using little more than info from one account (last 4 digits of credit card from Appstore account) to socially engineer Amazon customer support - http://www.wired.com/2012/08/apple-amazon-mat-honan-hacking/
Edit. Had some details wrong. It was a reporter at Gizmodo, and basically a collection of data was gathered from various online services (mailing address, last 4 digits of CC) to ultimately social engineer his Apple account and remote wipe his computer. A number of factors were involved, but ultimately he was done in by not having 2FA on google, and not backing up his machine.
Edit. Had some details wrong. It was a reporter at Gizmodo, and basically a collection of data was gathered from various online services (mailing address, last 4 digits of CC) to ultimately social engineer his Apple account and remote wipe his computer. A number of factors were involved, but ultimately he was done in by not having 2FA on google, and not backing up his machine.