OT, but all this datacenter talk reminded me of a video shoot I did at a VERY large DC. During the pre-shoot, on-site briefing with the DC's architect, when asked if we had any questions before starting, I couldn't resist...
me - "So I couldn't tell when we entered, but are all the doors air-tight?"
architect - "Airtight? No, but they high-efficiency insulated, does that answer your question?"
me - "Well, no... I was wondering how you're going to keep the Cloud in."

(cymbal hit, please)