On any Internet site, be it a mailing list, blog comment area, forum, or what have you, there is bound to be trolling. The less moderated the space, the more trolls there are likely to be. If you can't tell who the troll is at a particular point, look around. How many of the recent comments are yours? How many are in reply to you? The higher both numbers are, the greater the odds that you are the troll.