This article examines the domestic use of drones by law enforcement to gather information. Although the use of drones for surveillance will undoubtedly provide law enforcement agencies with new means of gathering intelligence, these unmanned aircrafts bring with them a host of legal and epistemic complications. Part I considers the Fourth Amendment and the different legal standards of proof that might apply to law enforcement drone use. Part II explores philosopher Wittgenstein’s notion of actional certainty as a means to interpret citizens' expectations of privacy with regard to their patterns of movement over time. Part III discusses how the theory of actional certainty can apply to the epistemic challenge of determining what is a “reasonable” expectation of privacy under the law. This Part also investigates the Mosaic Theory as a possible reading of the Fourth Amendment