Defined in two ways.
1.That a persons' privacy is being invaded my various unknown persons with a common agenda to hurt or discredit them. And the results are only understood by the person being harassed.
2. Paranoia envelopes every waking moment of a persons consciousness. The mailman, the clerk at the grocery store, a man walking his dog down the street, are in unison to invade and destroy this persons life.
Both are adequate to describe the possibility of gang stalking reality. For every positive there exists a negative. Not every apparent crazy person truly is. The question at hand is the the percentage.