Every year, Canada's Munk debates feature high-level, high-profile debates on burning policy issues. This year, they debated surveillance, and the participants were Glenn Greendwald and Reddit co-founder Alexis Ohanian on the anti-surveillance side and former NSA and CIA chief Michael Hayden and Harvard law professor Alan Dershowitz on the pro-surveillance side. Although the debating partners do a lot in this, the real freight is carried by Hayden and Greenwald, both of whom are more fact-intensive than the others.
I have a bias here, but I think that Greenwald wiped up the floor with Hayden (the post-debate polls from the room support this view). It was particularly useful to have Hayden being grilled by a well-informed opponent who was allowed to go after the easy dismissals and glib deflections. Normally, he gets to deliver some well-polished talking points and walk away — this was something I hadn't seen before.
This is just about the best video you're going to watch on the surveillance debate. It kicks off around the 30m mark.