Cars are probably among the easiest targets for thieves. You’re at risk whenever you park your car in an area that’s not secured. A thief has absolutely no problem breaking your car window using this trick.Thieves are using tiny ceramic stones — which are called “ninja rocks” — to easily break car windows.
image credit: hamburg.de
Ninja rocks are broken shards of spark plugs formed by smashing the ceramic portion of the spark plug with a hammer or other large object. Since they can quickly and quietly fracture the glass side windows on most cars, ninja rocks have been used in “smash-and-grab” auto burglaries since at least 1995.
They have no traditional association with the ninja or ninjutsu, only being named such due to their “silent but deadly” function in burglaries.A little itty bitty piece of porcelain chipped off a spark plug does much more damage to a car window and is so much more easy to use too. Just chuck it at the window! Tempered glass works funny like that.
The direct force on a small area applied by the sparkplug ceramic is enough to punch through the safety glass, which is designed to absorb great force over a large surface area without breaking.
However, ninja rocks are ineffective if the shards are insufficiently sharp, thrown with too little energy, or thrown against windshields, as these are made of a laminated type of safety glass, and therefore do not shatter.