[bananabreakfast]

A giant building full of hard drives is NOT a Google datacenter.

You're just comparing two storage numbers without taking anything else that running Google at a global scale requires.

[wz1000]

The NSA also monitors most of the worlds communications in near real time. A building full of hard drives is also completely useless without some sort of reasonably decent search and indexing capability, so I'm pretty sure the NSA built something for the task.