Instagram reinstated Rihanna's account and apologized for its shutdown Monday after some racy photos of her bare backside caused Instagram to disable it. "This account was mistakenly caught in one of our automated systems and very briefly disabled. We apologize for any inconvenience," said Instagram in a statement. Instagram clarified and added they never took down the singer's page after her account was blocked for several days after her photo of her picture by the pool and it was a simple system error.