This week we had:
Matt Bromiley, @505forensics, talking about NoSQL injection attacks and forensics to detect them. You can read more about it on his blog http://www.505forensics.com/

Matt Harrigan, @mattharrigan, of PacketSled, @packetsled, talking about his network visualization tool that is soon to have a free version released. You can sign up for the beta and get this into your hands at http://www.packetsled.com