DB use the same policy as it generally has in the past that until an over-the-air broadcast (eg Treehouse or TinyPop), these types of leaks should be blocked. Keep in mind that not all images tagged with one of these four episodes came from those leaks, but most since of last night would be. And if this is done, a warning message should be put into the main site bar.
OR
DB should warn users about these leaks and use spoiler warnings appropriately, as a main site bar notification.