Well, I sent out the first round of my nutcase letters this week, and I must say that I'm really happy to have found this board and all the great advise that is here. Wish me well with the process, and I'll keep you all in the loop so that I can share my own successes and failures as many of you have.
Basically it's a tactic to use when dealing with paid CA accounts, requesting verification. The premise is that you are a litigitous "nutcase" and you are suggesting that you plan on suing unless the CA's verify your accounts. The thought is that the CA's have more interest in collecting from current accounts, rather than ones that have been paid, and this will help to force a deletion. More info on the "nutcase rationale" is here: http://a1248.svwh.net/BoardFAQ.htm#Nutcase
Follow the above link, there are several posted in the FAQ section (or at least there are links to them as well).
Nutcase on the way/best next step? UPDATE: Well, the green cards have begun to roll in, and of course there has been no response to date from the CA's. Good, as this is exactly the type of response that I hoped for from them!!! The disputes are headed out this week, so everything is on schedule. The question now is what's the next best step for the 30 day mark? Do I go right after them with the estoppel letter, or send another validation request? These are all for paid CA accounts (the only things left on my CRA reports).