Thanks for the ping. I just skimmed this, but it seems like an excellent article, and I'm going to print it out and absorb it in detail over the weekend.
I would add one more comment, a conclusion I have reached on the subject of data collection. Gun grabbers often contemplate keeping guns legal but outlawing ammunition. I think we should consider a reverse approach regarding these government databases and systems - we can't do much about the tons of personal information floating about (the ammo), much of which is collected by private sources and is widely and easily available - but we can put tight controls on the guns that use them (the government databases and analytical systems).
These proposals are a good start towards that approach, but they also create a catch-22 - by making the debate over these controls public, they could provide enough information to terrorists to help them circumvent detection by the system. I think a better approach might be to have Congress set broad privacy guidelines and then have regular Congressional oversight of the implementation of those guidelines - but with some secrecy provisions that do not tip off how the system is supposed to detect terrorist activity. Otherwise, we shouldn't even bother, it will be a colossal waste of resources.