I often used to wonder how do burglars break the glass of cars quietly and run off with the GPS. A police officer recently presented in my housing community and there he mentioned the word “Ninja Rocks” as the technique used. The word “Rocks” above is used as a noun and not a verb. 🙂
I looked up the word and found that it means “Ninja rocks are broken shards of spark plugs. Since they can quickly and almost silently fracture the glass windows on most cars, ninja rocks are increasingly the tool of choice in “smash-and-grab” auto burglaries”.
I did some more research and discovered that auto glass panes (on the side) are under a lot of pressure from within and the impact of certain small pointed objects can shatter the glass even if a brick thrown at the glass does not.
Here is a video demonstrating how a brick fails to break the auto glass but pieces from a broken spark plug are able to do it.