Extend your index and pinky fingers. Curl the middle finger and ring finger downward. If you then press your thumb inward, over the bent middle and ring fingers, you will have made Spider-Man’s web shooters, the secret heavy-metal devil symbol, hook-’em horns, or, what I call here, “the whammy.” All of those could be considered aggressive gestures.
Put your fingers in the same position but extend the thumb outward, to the side of your hand, and you have the American Sign Language gesture for “I Love You.”
It seems that the thumb position is key. Point your thumb in the wrong direction and the meaning and intent completely change. Wars have been started over lesser mistakes.
It also seems to me that the main reason Spider-Man stories all focus on his life as a teenager and young man is that his later life will be spent fighting his greatest enemy: carpal tunnel syndrome.