Emphasis Preaching Journal

In Britain during the darkest days of WW2, blackout was practiced. The idea was to have not even a single light showing so that if an enemy aircraft was flying overhead the crew would not know that a dense population was below. Imagine the terrible fear that existed during this time necessitating such an exercise!
In that scenario even a seemingly minuscule flame from a lighted match could pierce the darkness so pervasively that the aircraft bombing crew would be "tipped off that there was human activity in their range.