There is a bullet proof vest called
Dragon Skin that works off the same principle. Rather than using large plates of ceramic, they use multiple ceramic disks that are arranged like scales (hence the name dragon skin). If a large plate is hit and shatters, it's ability to deflect bullets is greatly compromised. The force required to break the ceramic is what actually stops the bullet. It is similar to styrofoam inside a bike helmet. While the foam is actually pretty hard, it shatters on impact absorbing the energy of the impact.
I still don't think I'd walk around with flooring tiles duct taped to my body though...
