An exploit has caused Bloodborne to be brought offline for “emergency maintenance,” according to Sony.
According to a post on the PlayStation Japan site, the team is conducting maintenance on the game servers, which should be completed in “a few days.”
On reddit, one of the game’s developers Tim Wernicke stated he was unable to provide specifics on what the exploit was, but thanked users of the Bloodborn sub-reddit for pointing out any issues with the game.
Kotaku speculates the “exploit” in question is one which reared its head after The Old Hunters DLC was released. It basically gave players the DLC for free.
This would definitely constituent taking the game’s servers offline for a “a few days.”