NSA leaker Edward Snowden addressed a packed auditorium at South by Southwest today, speaking via livestream from Russia. In response to questions from ACLU program director Ben Wizner, Snowden called on internet service developers to thwart the NSA by making strong encryption ubiquitous. In conjunction with Wizners co-presenter Christopher Soghoian, Snowden called for end-to-end encryption that would keep the NSA from snooping on data simply by tapping into servers or internet backbone cables.