Most of us seek a mutual exchange of ideas in our conversations, but not all of us. Most of us are open to the possibility of intellectual change, but not all of us. We get many comments at this site, most of them thoughtful, many of them really challenging to my pre-conceived beliefs. I revel in those challenging comments. In the past few months, though, I have struggled with how much leash to give to several visitors to this blog even though they tried to A) monopolize the conversation, B) preach, C) impose their favorite two issues upon every post, and D) ignore clearly-stated bona fide points made by others. In addition to using these ignorant and aggressive tactics many of these comments clearly have their facts wrong (some claimed that Obama is a terrorist; others claimed that God Himself wrote the Bible in King James English). When these sorts of people join in-person real-time conversations, almost all of us employ similar strategies. We extricate ourselves from those conversations so that we can join some other conversation. We also take steps to avoid spending time in the same room with those sorts of people on future occasions. A blog is not exactly a conversation, but it is a lot LIKE a conversation. What, then, should a moderator do when conversation-killers attempt to roost at a blog? For many months, I've struggled with this question.