How celebrities' nude photos get leaked

How did private, nude photos of Jennifer Lawrence and other celebrities get leaked all over the Internet Sunday?
It was a combination of weak passwords, easy-to-guess security questions and a bug in Apple's photo backup service that has since been fixed.
On Tuesday, Apple (AAPL, Tech30) concluded hackers were able to force their way into celebrities' private photo collections by repeatedly guessing passwords -- or answers to their security questions.

This was possible, because of a bug in the system Apple uses to remotely store photos and documents: iCloud.
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Well-guarded systems only let users guess passwords a handful of times before blocking access. But until this week, Apple's iCloud service allowed people to guess passwords over and over again. It would never lock out. Eventually, hackers hit it right.
Also a likely culprit: the "forgot my password" feature. If you don't remember your password, the system asks you security questions to grant access. These actresses, models and singers lead public lives, and answers to questions about their past are easily found on Wikipedia and elsewhere.
It's similar to what happened to Alaska's former governor, Sarah Palin. Hackers accessed her personal email account. One of the security questions she had set to retrieve her password was her birthday.