mis•chief
n.

1. Behavior that causes discomfiture or annoyance in another.
2. An inclination or tendency to play pranks or cause embarrassment.
3. One that causes minor trouble or disturbance.
4. Damage, destruction, or injury caused by a specific person or thing.
5. The state or quality of being mischievous.

Problems worthy of attack prove their worth by fighting back.

- Paul Erdos (1913-1996)

Joel Knight