I engaged a nimrod troll over at fandom_wank a year or so back, in a thread about Death Note. I was originally talking with someone who hadn't gotten very far in the series yet, and a few days after the conversation had ended the troll - an anonymous poster - popped in and informed her of the Big Spoiler.

Only this troll was an idiot, because instead of replying to the person I was talking to, who would have gotten the comment notification, they responded to me. So I replied, calling them an idiot and a coward for not signing their name, and the replied to me, and so on. I asked them why they liked bursting someone's bubble over something as simple as respecting the author's pace of revelation and they never gave a really satisfactory answer. They also never quite grasped that the person they were attempting to spoil never got any comment notifications, since they replied to me and not them, and thus was never actually spoiled. Idiot!