Google has some very cool data centers. The video below is a guided tour of one. It's pretty interesting to watch. Students love seeing this too. It's also a great learning resource to discuss energy, environment, data, technology and security.
The data center campuses are very secure, with very limited access. Security includes badges, iris scanners, cameras, guards, multiple fences and even under-floor intrusion detection systems.
The centers run pretty efficiently and at higher temperatures than most. In typical Google fashion, employees can bring their dogs, decorate their work spaces, uses scooters and bicycles to get around, Google's colors are everywhere and they even have a foosball table. The server racks are custom designed and built, as are the servers, and data security is high. Failed drives are wiped and physically destroyed.