Well, not really a debate, but they each respond to the same questions… Excellent discussion of the underlying issues at play.
From TalkingPointsMemo.com: http://tpmdc.talkingpointsmemo.com/2013/06/obama-and-snowden-debate-nsa-surveillance-programs.php?ref=fpb
To ensure public safety, there may be a requirement for some level of governmental surveillance. The question is: how can we ensure public safety through surveillance while still maintaining individual privacy? This is one of the more important issues of the day, and requires a socio-technical level of research that expands the traditional boundaries of academic disciplines.
Meanwhile, here’s an interesting and historic look at public surveillance in the US.
From ProPublica.org: http://projects.propublica.org/graphics/surveillance-timeline