Would government access to the mental impressions and memories of individuals be an unreasonable search or seizure? In this article I explore technology-facilitated law enforcement access to information stored within individual human minds and what barriers the Fourth Amendment may present to such invasions. I begin by reviewing the development of brain-computer interface technology and its current and probable near-future capabilities. I then explore the right protected by the Fourth Amendment, and how the reasonable expectation of privacy analysis currently favored by the Supreme Court may interact with such technology. I conclude that some particularly invasive thought access techniques are probably not a constitutional "search" under that approach. I propose that certain aspects of the property-oriented view of "[t]he right of the people to be secure in their persons" extant prior to the Supreme Court's decision in Warden v. Hayden may remain applicable when the corporeal mind is the subject of a search and seizure. I also promote the notion that the nature of the right should be grounded in the words of the Amendment, with a focus on the enumerated right to personal security rather than the unenumerated and often arbitrary "reasonable person" privacy analysis. I then attempt to formulate a definition of the "inviolate person," a boundary beyond which a governmental intrusion is per se unreasonable. I offer several justifications for this demarcation beyond the constitutional argument, and conclude with a brief argument for a two-tiered exclusionary rule with additional consequences for egregious constitutional violations.