One of the most dangerous aspects of SOPA and other copyright proposals is the idea of moving enforcement and liability further down the stack of technology that powers the internet, even all the way to the DNS system. Although SOPA's DNS-blocking proposals were heavily criticized and the bill ultimately defeated, the idea of deep-level copyright enforcement has lived on and been implemented without changes to the law. This week our returning guest, law professor Annemarie Bridy, discusses how private agreements have quietly recreated some of the worst aspects of SOPA.