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.