Facebook announced Monday that it will allow more access for third-party developers, a move designed to open the door to potential revenue streams and help it hold off social network rivals like Twitter. “For the first time, we’re opening the core Facebook product experience — the stream — with the new Facebook Open Stream API,” wrote Ray C. He on the Facebook Developer’s Blog. However, at least one privacy advocate fears the network may instead lift the lid on a Pandora’s Box full of personal information abuse.