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. They have no traditional association with the ninja or ninjutsu, only being named such due to their "silent but deadly" function in burglaries.
Read more about Ninja Rocks: How They Work
Famous quotes containing the word rocks:
“Lord, what a thoughtless wretch was I,
To mourn, and murmur and repine,
To see the wicked placed on high,
In pride and robes of honor shine.
But oh, their end, their dreadful end,
Thy sanctuary taught me so,
On slipp’ry rocks I see them stand,
And fiery billows roll below.”
—Isaac Watts (1674–1748)