Google recently released a video shows the extremely robust physical, data protection and operations security of its data centers. Google does not allow tours of its facilities and limits physical access to only necessary employees. Access is controlled by special badges and in some cases retinal scanners. Wait until you see how they dispose of hard drives. Fascinating stuff that serves as a shining example of security done right.
[kml_flashembed movie="http://www.youtube.com/v/1SCZzgfdTBo" width="600" height="390" wmode="transparent" /]