Although the media quickly dubbed him the "subway vigilante", all that did was prove that the media hadn't a clue what a "vigilante" was. Acting in self-defense does not a vigilante make. If Bernie had set out to seek revenge for past wrongs, then he would have been a "subway vigilante".
What Bernie Goetz actually was, however, was a textbook example of what not to do after a self-defense situation. Don't be a Bernie:
1) Resist the urge to make "Dirty Harry" quotes.
2) Do not flee the scene.
3) Do not ditch the weapon in question.
4) Keep your cakehole shut and call your lawyer.