What defines a reasonable expectation of privacy?

A reasonable expectation of privacy is primarily determined by the degree of control an individual has over their personal property and the information contained within it. Control over property owned or possessed means that an individual has the autonomy to decide who has access to it and to what extent. This concept is foundational in discussions of privacy because it emphasizes the right of individuals to manage their personal spaces and information without unwarranted interference from others, including authorities.

In contrast, broad access to personal data would negate privacy, as it suggests that many individuals or entities can access private information without restriction. Similarly, being present in a public place inherently implies less privacy, as one is subject to observation by others. Lastly, open visibility to others aligns with a lack of privacy since it suggests that what one wishes to keep personal is accessible to anyone. Thus, control over one's property stands as the most defining trait of a reasonable expectation of privacy.