Inadvertent radical transparency
A blogger on Tuesday reported on the security flaw, and used it to publish a photo from Mr. Zuckerberg's private collection. Others then used the flaw to publish further photos from Mr. Zuckerberg's collection, including images of the Facebook CEO preparing food in a kitchen and distributing candy to Halloween trick-or-treaters.
It wasn't immediately clear how long the Facebook security flaw was available on the Web, or how many of the site's more than 800 million users were affected. But the company attributed the problem to a recent revision of its software.