When it comes to criminal investigation, time travel is increasingly possible. Despite longstanding roots in traditional investigation, science is today providing something fundamentally different in the form of remarkably complete digital records. And those big data records not only store our past, but thanks to data mining they are in many circumstances eerily good at predicting our future. So, now that we stand on the threshold of investigatory time travel, how should the Fourth Amendment and legislation respond? How should we approach bulk government capture, such as by a solar-powered drone employing wide-area persistent stare technology? Is it meaningfully different from civilian equivalents that find their way into government hands, whether it be tomorrow's drone flight, or today's record of all of our internet activity compiled by our internet service provider, or a current record of all of our movements compiled by our mobile phone company? What of targeted time machines such as government over-seizure of digital data in every computer search? This Article considers the benefits and costs of these miraculous timemachine technologies, including as evidenced by several recent court opinions. Considering the very serious privacy implications--from the individual to the relational and societal--we have good reason to be wary of their coming ubiquity. Yet perhaps in very limited spheres we should welcome them, going so far as to entirely abandon front-end acquisition restrictions and rely solely upon ex post access, use, and disclosure limitations to protect the security in our persons, houses, papers, and effects. I suggest that one such sphere might be law enforcement body cameras, an instance in which full capture has great benefits, and via which we can experiment upon the utility of solely ex post restraints. [ABSTRACT FROM AUTHOR]