In today’s era surveillance is the prime requirement of the society as act of violence in the world is rapidly growing. In past decade Precarious activities were recorded through the video cameras. Due to the limitations of the human observer, this manual system proves to be inefficient in detecting precarious events. This leads to the development of the automated systems which can detect suspicious activities, behavior or objects automatically and notification is sent to the concern authority. In this paper various novel approaches are discussed and detailed analysis is presented.