Normally I'd put this into the comments on a blog rather than jumping to my own blog, but I think it's worth saying in a full-scale blog post. It is a very, very bad idea to speculate in any sort of public forum about the identity of the YDIS guy, or, really, anyone who stays anonymous on the net. I don't mean to sound like I'm scolding Austrodavicus, although I guess I am, but mainly I want to point out something that he may have missed in making a public guess about who the YDIS guy might be.
The problem is this: whoever gets accused of "being" someone else has no way to refute that accusation. The accuser has basically thrown mud on someone who cannot provide any proof that the accusation is invalid. You can't prove the negative. In fact, even if the YDIS guy got on his blog and "admitted" to being someone, could you necessarily believe that statement? Of course not. Most likely the YDIS guy would think it was totally hilarious to see someone else being vilified in a case of mistaken identity.
Austrodavicus doesn't make a completely blind accusation, since he provides links to a couple of places where his accused person makes message board posts that are reminiscent of the writing style of YDIS. But I can think of at least a couple of people who can and do occasionally write that way when they are pissed off. Taking a couple of quotes in isolation, cobbling it together with someone's known opinions (the guy accused by Austrodavicus doesn't, for example, think highly of the blogging scene) might be fine for private speculations between buddies in a context like private messages or emails, but it creates a possible public slander of someone who is innocent and can't prove it. That mud sticks; it creates suspicions in peoples' minds; it is not fair.
I think that post is something where Austrodavicus didn't really think through the possible consequences if he's wrong about his guess. Not that I personally think Bill would care one way or the other, but what if he does? Part of the accusations that have been leveled at YDIS is that he targets people without knowing them personally, creating a lot of pain for someone out of the blue if they happen to be sensitive about it. Austrodavicus has done just that, even if Bill didn't care. Who can say if he cares or not? Who can clear his name of that kind of accusation? Making a public speculation about the identity of a very-disliked person like YDIS shouldn't be done unless there's a lot more proof than a few posts where the tenor or the content is similar. There is no way to disprove it, and thus no way to repair a reputation.
I've had this sort of thing, in a much less problematic form, leveled at me before, the most upsetting one being when someone claimed I had written something on the net that I'd never written. Try to disprove that accusation when it's possible for someone to delete posts, and where the assumption would simply be that I'd deleted the never-existing post.
If bloggers were to get into a public speculation and counter-speculation, naming names, there will be lots of people who get their reputations attacked -- and only one of those accusations would (or might) be correct -- every single other accusation would have been leveled at an innocent person. And it could never end, since even an "admission" by YDIS would be utterly suspect.