"In the 1970s, the Supreme Court handed down 'Smith v. Maryland' and 'United States v. Miller', two of the most important Fourth Amendment decisions of the 20th century. In these cases, the Court held that people are not entitled to an expectation of privacy in information they voluntarily provide to third parties. This legal proposition, known as the third-party doctrine, permits the government access to, as a matter of Fourth Amendment law, a vast amount of information about individuals, such as the websites they visit; who they have emailed; the phone numbers they dial; and their utility, banking, and education records, just to name a few. Questions have been raised whether this doctrine is still viable in light of the major technological and social changes over the past several decades. […] With these legal, social, and technological trends in mind, this report explores the third partydoctrine, including its historical background, its legal and practical underpinnings, and its present and potential future applications. It explores the major third-party doctrine cases and fits them within the larger Fourth Amendment framework. It surveys the various doctrinal and practical arguments for and against its continued application. Lastly, this report describes congressional efforts to supplement legal protection for access to third-party records, as well as suggesting possible future directions in the law."
CRS Report for Congress, R43586