Modern privacy-preserving mechanisms typically address different methods of concealing private data during communication through a public network or storing it in a physical device. The curious third party, who observes the communication traffic or the stored data, cannot distinguish whether the traffic or storage contains any imperceptible secret or is simply innocuous. This paper is a comprehensive study of different non-conventional privacy mechanisms and characterizes them based on their intuition, effectiveness, efficiency, and vulnerability. The paper broadly discusses three topics—deniability, obfuscation, multiparty computation, and interoperability.