Delightful vitrol or troll fodder

When can we be vitriolic on the interwebs and have it not be food for trolls? How can we be hyperbolicly critical without being rightfully called a troll ourselves. I find it very therapeutic to vent my spleen into the anonymous void of the internet but am forever worried that if I do it somewhere very public that I will, instead of garnering giggles, be prompting cyber-malcontents to shit in the forum. And while a certain amount of hypocrisy is fun and funny I don't think I would like to lose what little credibility I have by lambasting trolls while at the same time making monstrous comments about other subjects? I guess it is time for me to go out and find somebodies guide to the subject of internet posting.