Jacob Appelbaum at the 29C3 keynote about the new, top-secret NSA building in the US and a couple of other things, what gave me the chills - mainly how the US government is - let's say "performing".
You can watch it on YouTube.
Or if you want to get the video, the filename is "29c3-5385-en-notmydepartment*" on any of 29C3's mirrors.