No matter your industry, you are going to have people who love you and people who hate you, but the vast majority of people won't have an opinion about you.
Too many times, we listen to the people who hate us. We respond to all their negative comments and they come right back with even more negative comments. We continue to respond and soon become frustrated because we can't change their misguided (or at least what we believe to be misguided) opinion and we fear their comments will damage our reputation.
Responding to them is fine, but don't get lost in an argument with haters. Explain why they are wrong (if they are) and move on. The back and forth helps no one and actually fuels the hater because someone is listening to them. It is much more important to communicate back and for with the people who love you and the people who don't yet have an opinion. You will never get the haters to like you, so don't waste your time. Use your time to build a relationship with people who will like you. Build a big enough group of people who love you and soon they will respond to the haters.
Most people recognize a troll as a troll. Responding to all of their hate gives them credibility. Spend your time engaging and developing fans and the trolls will move on.