Several comments here...
First off, I live 1000+ miles from my last congregation, so we'll see how determined they are. I told my father of the announcement at the elder meeting to seek out the inactive ones. He got uncomfortable, probably because I know such a thing (he's not an elder anymore), and said he wasn't aware of that. I asked him to let me know whether anybody was looking for contact info on me and he's agreed to do so. Since my dad is, was, and seemingly always will be very regular and active, he would be a logical first step towards finding me and my brother without having to employ searches that cost money. My brother, who still lives in the area, called in some contractors to estimate some work in his house. It was 2 of our old elders. So they know where he is.
As for how far they will go..., well, I wouldn't put it past some enterprising young elder to subscribe to online services just for the fun of playing detective and tracking somebody down, using his own resources and money. After all, that sort of thing can be a lot more fun than filling out service reports. And actually, it isn't even that hard to do for free. Something like US Search lets you plug in a name and approximate age and shows you cities, but you have to pay to get the details. But, once you know the city, nine times out of ten, they're probably listed in the local white pages (or online white pages) and that's all it takes, without paying for expensive searches.
As far as publisher records go, I've seen various reports. Some say indefinately, others say something like 7 years after the person has gone inactive, they get tossed.
