For instance, replacing useful articles with poorly-written, poorly-linked, semi-coherent rants that use an idiosyncratic vocabulary that nobody else understands. Or, trumping up supposed issues of systemic bias and tarring anyone who disagrees with the label of "sysop" (equivalent to "witch" or "devil" in the heroic troll's vocabulary). Or, simply hijacking (or attempting to hijack) various large public wikis in service of what appears to be an odd pseudo-Green agenda, or possibly just for the thrill of annoying people without any possibility of retribution - hard to say. Heroic trolls are naturally too lazy to set up their own projects, but love to stomp all over others' - perhaps they take delight in castle jumping.
Very little honour may accrue to those who take such "responsibilities", and stigma will likely accrue also via anyone who sees through the trolls' silly masturbatory fantasies of importance. Naturally, the individuals who believe in "heroic trolling" get some sort of thrill out of their electronic chest-beating and dung-flinging; why they do will forever remain a mystery.