First I want to say that I don't agree with publicly disclosing the "identity" of people who doesn't want to be found. I also don't think doing so "originates" from any good personal quality. That being said, I do remember this [1] talk from last CCC to be interesting from a technical standpoint.

[1] http://events.ccc.de/congress/2009/Fahrplan/events/3468.en.h...