USA TODAY 
March 26, 2012
SOMEWHERE ON THE EASTERN SEABOARD – Prisons are easier to enter than Visa’s top-secret Operations Center East, its biggest, newest and most advanced U.S.  data center.
The 8-acre facility looks like any other industrial park in a sleepy suburb. But the serene setting masks hundreds of cameras and a crack team of former military personnel. Hydraulic bollards beneath the road leading to the OCE can be quickly raised to stop an intruding car going 50 mph. Any speed faster, and the car can’t navigate a hairpin turn, sending it into a drainage pond that functions as a modern-day moat.
The data center resembles a fortress, with dogged attention to detail. It can withstand earthquakes and hurricane-force winds of up to 170 mph. A 1.5-million-gallon storage tank cools the system. Diesel generators onsite have enough power, in the event of an outage, to keep the center running for nine days. They generate enough electricity for 25,000 households.
Once you get clearance from a guard station, get an OK from a roving security guy in a golf cart, and surrender a photo and fingerprint inside, the adventure begins.
There are plenty of reasons for the airtight security. Billions, in fact.