Sony is emphasizing social interaction with the PlayStation 4, even including a "Share" button to easily show off your experiences to friends and stalkers. But it recognizes that sometimes developers won't want to let you show off things like spoilers, so it's giving developers access to disable it selectively.
"There will be parts of a game that the maker does not want people to be able to see," Sony Worldwide Studios president Shuhei Yoshida told 4gamer (translated by Edge). "For example, on Vita, developers can in certain scenes disable the feature that lets users take a screenshot, and (the Share function) will have a similar mechanism. The creator may not want to make video of the final boss sharable, for instance."
He didn't mention just how extensive this ability would be, if developers would only be able to disable small portions, or if they could cut off large swaths of a game. Yoshida said that his own desire to make sharing easy came from Dark Souls, when he was too busy to play but wanted to watch videos. The suggestion of a dedicated share button came from a member of the production staff, and the team instantly recognized the value.