Another innovation in physical security, from the Security 101 site: Security window film.
“Security film consists of one or more layers of polyester film,” writer Corey Tyriver explains. They are then overlaid together with potent sealants. The end result is a film ranging in thickness from about 4 millimeters to 15 millimeters or even more. The thicker, the better. The engineered film basically keeps glass from shattering upon impact.”
A further attractive feature: “It can be completely undetectable while offering the same view outdoors.”