The only harm he caused was taking justice into his own hands. Nothing of what he actually did was an injustice though, unless we are going to start throwing out Leviticus.
He did nothing worse than burning down a porn shop or shooting an abortionist.
A sane society would have already done these things though.
Hey now! I'm excusing the man because of his issues of being abused as a child. Burning down a porn shop, or shooting an abortionist makes one just as guilty as the other. I cannot find it in my heart to blame the guy for offing that POS, but I am disgusted by people who go around playing vigilante out in the "free world".