One possible use for this GPS data occurs to me.
Gerrymandering. The manipulation of the borders of voting districts, to assure that Congressman X of the 45th congressional district, will always have a solid Democrat-voting majority. Makes districts look like paint splatters on a map sometimes, but hey, no one said it would be pretty, just effective.
Can also be used to CURE gerrymandering, of course, but give me a break.
Give me a list of addresses, party registrations from voter-reg data (freely available), and now the GPS coords of each house, and I'll write you a computer program that produces Democrat majorities (or Republican majorities, take your choice) for EVERY state that votes by congressional districts.
How? Easy.
You want California to elect more Democrat congressmen to the U.S. House of Reps, than Republican congressmen? I'll set up most of the districts to have 55% Dem majorities, and a smaller number that have 95% Republican majorites. Even if Repubs outnumber Dems in the state, I'll give you 60 districts that elect Dem congressmen while only 20 elect Repubs.
With EXACT knowledge of the physical location of each Repub and Dem voter, I'll guarantee delivery of the exact results you want. Some of the districts might stretch from San Diego to Geyserville, winding thru one neighborhood after another to pick off Republican households while avoiding Democrat ones, but do you care?
Redistricting is a possibility, no doubt. With an exact knowledge of where the Democrats and Republicans live, the legislators will be able to fine tune their gerrymandering and stay in power indefinitely.
We did try to put an end to the legislators drawing their own boundaries in California, but it didn't pass. Check that out here.
And here is another example of how electronic data is readily available to anyone, whether they are a part of the government or not. Did you contribute to pass or not pass the gay marriage bill? If you did, then your name is on this list. Check it out.