Police surveillance ability and information gathering capacity have a dynamic relationship with technology. Greater advancements in technology make it easier for the police to surveil individuals and collect information. This state of affairs leads to heightened concerns over Fourth Amendment protection. This issue has most recently played out in the context of police collecting cell phone location data. Courts disagree on whether and to what extent this data garners Fourth Amendment protection. Underlying this disagreement rests a hitherto overlooked tension between two interrelated Fourth Amendment doctrines—the third-party and the public disclosure doctrines. While both vitiate privacy protection and are commonly associated together, they rely on very different triggers. This Essay provides a detailed analysis of these distinct features in an effort to harmonize the doctrines in the cell phone location data context.