What is the origin of the idiom "five-finger discount" and when to use it?

The idiom "five-finger discount" likely stems from the idea that individuals use their five fingers to quickly take something without paying for it. This phrase has been in use since at least the mid-20th century. It is now used to describe stealing merchandise from stores in a somewhat playful or casual manner, but it should not be taken lightly as it promotes dishonest behavior.