Motion detectors are usually passive infra-red (PIR) sensors - no lasers involved. Unless you can cite a consumer-grade laser-based motion detector, I think this means Google's data centers are protected by slightly higher level gear.
> This high tech device creates an invisible infrared beam up to 60 feet long and sounds a loud alarm, pleasant chime, or mutiple chimes when the beam is crossed.
From my understanding (after doing a few weeks of research on this for my own home security) the current "top of the line" tech is the Tomographic motion detectors which build up a mesh.
It has been commercialized by a security company named Xandem, some info on it:
