@neologic2k
neologic, I take it you've never done any work in a telephone exchange!
These places are not typically manned out of hours, if manned at all. The last exchange I worked in the physical security consisted of the usual stuff (swipe cards, that sort of thing) and a video camera; the door locks were released remotely after you'd phoned the security people and they'd clocked you on the video cameras.
Telephone exchanges are a long way from being 'data centres', even in this day and age.
Given that your modern high-tech thief's idea of a wiring tool is a set of bolt cutters, I'm quite sure they could be in and out well before plod or anyone else was on the scene.