Under the search incident to arrest doctrine, police may search the entire body and immediate grabbing space of an arrestee, including the contents of all containers, without any probable cause. Because almost all traffic infractions are arrestable offenses, police have enormous opportunity to conduct such searches incident to arrest. In the near future, these already high-stakes searches will become even more important because millions of drivers will not only possess containers that hold a few scattered papers, such as wallets or briefcases, but also iPhones—capable of holding tens of thousands of pages of personal information. If current Fourth Amendment jurisprudence is extended to its logical conclusion, officers who arrest drivers for traffic infractions will be permitted to search the call histories, text messages, email, photos, movies, and internet browsing history on iPhones with no suspicion of wrongdoing whatsoever. This Article demonstrates how the full contents and multiple applications of iPhones can be searched without a warrant or probable cause under existing U.S. Supreme Court precedent. The Article also offers approaches courts and legislatures might adopt to ensure greater protection for the soon-to-be pervasive iPhone devices. Courts and legislatures can attempt to minimize this invasion of privacy by changing the legal rules to require that searches be related to the purpose of the arrest, by limiting searches to applications that are already open, by restricting suspicionless investigation to a small number of discrete steps, or by limiting searches to data already downloaded onto the iPhone, rather than data that is merely accessible through the iPhone’s internet connection.