Thanks for the clarification! That does make sense. I do wonder about whether calling trolls out really gives them the attention they want, though. At least judging by the trolls I've seen here, it seems to me that what they crave are the sympathetic responses and definitely don't want to be called out. Trolls on other boards are sometimes different, but when the modus operandi is making up incredibly sad and dramatic stories, I think the troll is after positive, not negative, attention. In other words, feeding this particular kind of troll would actually be continuing to give understanding and sympathetic advice--that's the "food" they seem to want most. Once someone expresses their concerns publicly, I'd think this sort of troll would be much more likely to move on because few people would believe their stories and offer sympathy any more.
But I'm just conjecturing. It's also likely that calling trolls out publicly creates unnecessary drama, and in the end, it probably doesn't matter too much.