I just watched an episode of CSI where the investigators are sneaking up on a suspect who is using a terminal at one end of a large data center. The data center in question contains dozens of racks, all chock full of active servers. The CSI dudes are trying not to alert the suspect, and they’re sneaking ever so quietly, and they’re using those military-style hand signals rather than saying anything out loud, because the suspect might hear them. During this sneaking scene, one of the agents accidentally slightly bumps into a box or something, and the suspect hears this and does a runner.
And, if you’ve ever spent any time in a data center with dozens of racks full of active servers, this is all very amusing.
You know that whirring noise the fans in your home desktop PC make? Well, a rack-mount server designed for data center use doesn’t have to worry about its fans being used in a home environment, so it’s much louder. Imagine that. Now multiply it by a thousand, then add the sound of some big-ass heat exchangers and maybe chilled water pump noise, and that’s pretty much what a data center sounds like. It’s loud as hell. You could put on full plate armour and only use the Monty Python Silly Walks to sneak up on a suspect, and you’d still have a pretty good chance of not being heard over the ambient sound.
For shame, CSI! FOR SHAME!
 You know the hand signals I mean. The ones where you play rock paper scissors, except you always choose rock. Or where you hold up three fingers and then point in a direction and then the other guy nods to acknowledge that you have pointed and he’s seen you. Those hand signals. Yeah. That’s them. Those ones.