The Darknet (sometimes called the Dark Web) works on the Tor browser, free software that masks your location and activity. Originally designed by the Naval Research Lab, Tor receives 60 percent of its backing from the State Department and the Department of Defense to act as a secure network for government agencies as well as dissidents fighting oppressive regimes. It is a privacy tool that has been used for both good and evil. Over the past decade, Tor has empowered activists to spread news during the Arab Spring; it has helped domestic-violence victims hide from online stalkers; and it has allowed ordinary citizens to surf without advertisers tracking them. But at the same time, the Darknet, which Tor enables, has become the primary cove for criminals like Ross Ulbricht, imprisoned founder of Silk Road; the hackers behind the recent Ashley Madison attacks; and the international crew busted by the feds in July. As an instrument for both activists and criminals, Tor presents an increasingly difficult problem for law enforcement to solve — exacerbating the hapless game of whack-a-mole facing those who try to bring law to the most lawless part of the Net. And the battle over the Darknet's future could decide the fate of online privacy in the U.S. and abroad. ... Since its inception in 1923, the NRL has been the military's most esteemed research and development lab, inventing everything from radar to GPS. In 1995, Syverson and his colleagues conceived a way to make online communications as secure as possible. The idea was to provide a means for anyone — including government employees and agents — to share intelligence without revealing their identities or locations. With funding from the Department of Defense, Syverson brought on two scruffy graduates from the Massachusetts Institute of Technology, Roger Dingledine and Nick Mathewson, to help bring his vision to life.