@mhansen: the answer to your question is both yes and now. Meaning that I actually have two different Google accounts and therefore two of all those Google services: Adsense, WMT and GA. I've had it like that for some 7-odd years for personal and business purposes but in the end it's all one owner, of course. Banned sites belong to both accounts. So, do you think they have a problem with me personally?
I don't host all the sites on the same server but I do use the same registrar (and it's private so, technically, my contacts are the same as millions of other domain names).
Burning the whole house with a single match sounds like an efficient way of killing someone's business but I just can't picture Google to care enough to do something like that.
I'm looking at my logs and testing HTTP headers returned in hopes to spot a technical issue but for something like that to happen, it looks like I'd need to have one hell of a technical issue.
I don't pretend that the sites are extremely important to the fabric of the Web (which one individual site is?) but to "earn" a ban there would have to be something egregious. I know enough to not have done anything so bad, at least not intentionally.