This diary is here because, mostly, the comment thread on the petition diary to unban Tocquedeville is now insanely long.
I do not believe I have ever seen a diary with 2300+ comments on it before, as that one, which certainly attests to the passion this community has about the subject of CTs and banning.
I have some thoughts on the matter that I'd like to share, which are a bit more extensive than I can really treat in a comment over in that diary.
First, the notion that CTs are verboten.
Yes, It's Kos's site (well, KosMedia's site), and he can do what he wants. What he wants, as has been stated and hosannahed many times, is a vibrant community of smart people kicking around the issues of the day and helping get Democrats elected.
To that end, Kos and his legion of crack web programmers have created a pretty awesome set of mechanisms that actually enable said community to self-moderate. And guess what? It works amazingly well.
So, while Kos can establish a set of bannable-offense forbidden topics if he wants, I have to observe that (to me, at least) that feels like a violation of the core principle on which this site operates: trusting the community to be smart and do the right thing.
Second, the chilling "Gotcha" aspect of forbidden topics.
Ignorance of the law is no excuse, as they say, but I'll admit this much up front: until today, I had no idea that conspiracy theories were "subjecta non grata" on Daily Kos. None. I've been kicking around here since sometime in 2006, with varying degrees of activity and participation, but I had no idea.
It begs the question, if there's one forbidden topic, are there more? Where do I look to find out? How do I know, when I decide to write a diary on some topics that interests me, that I'm not accidentally stepping on a land-mine?
I scan the Rec list and the recent diaries list and see postings on topics from A to Z. It gives the impression that anything (so long as it's well written and supported) is fair game. And yet, it's not. There are landmines to watch for, if you know where to look.
Having foridden topics at all, IMHO, creates a chilling effect in the community as a whole. And that's a bad thing both for the health of this site and for the strength of the progressive movement.
UPDATE: I've been pointed to the section in the FAQ (here where this banning rule is laid out. Maybe I read that back in the mists of time, maybe not. I can't remember. Knowing that CTs were an actual problem back in the day does make me more inclined towards Kos's position. Thanks to all who pointed that out to me.
Third, the difficulty with CTs in particular
The subtext of Tocquedeville's diary entry is, I think, an incredibly valid point that he didn't bring up explicitly. That, I think was a mistake. The point is this:
Ideas that sound like crackpot CTs may, when actual evidence comes to light, turn out to be true.
With 9/11 LIHOP/MIHOP hypotheses (I won't call them theories, because I'm pedantically geeky like that), there's enough credible and semi-credible evidence that these hypotheses are somewhere in between "totally wacko" and "accepted, proven truth".
That's just one example. Let's make up another one--say, NASA caused the 2005 tsunami with from space with a secret earthquake-beam weapon. Clearly wacko. But if evidence started coming to light, at what point would Kos suddenly decide "well, ok then, that's now a non-forbidden subject"?
I have no idea. Does Kos? Would it have to be on a case-by-case basis? Given the nature of CTs generally, I imagine it would. And therein lies the problem. The sliding-scale between "wacko CT" and "proven, supported claim" makes it enormously difficult to be consistent in treatment of these topics.
Conclusion
As I said, it's Kos's site, and he can do what he wants. But in the balance, I think that both banning CT discussions and the practice of having forbidden topics generally are mistakes.
Trust the community. We know, both anectotally from the success of this site, and empirically from the work of people like Nate Silver, that there is real wisdom in crowds.
Let people discuss whatever they want, and trust the Kossack crowd to be wise. If someone wants to spin conspiracy theories about Bush's grandfather secretly funding the nazis to build robot A-bomb factories on the moon, fine. Trust the wisdom of the crowd here to troll-rate that crap into oblivion.
Likewise, if someone wants to discuss 9/11 LIHOP/MIHOP, well, let them. But again, let them take extreme care in constructing a well-written, well supported argument, lest they suffer the same fate as the nazi moon robots.