Presented at USENIX NSDI.

Abstract: http://www.usenix.org/events/nsdi11/tech/techAbstracts.html#...

Paper: http://www.usenix.org/events/nsdi11/tech/full_papers/Wang_Yo...

In some densely populated Asian cities, 690 meters will encompass tens of thousands of people.

A circle with a 690 meters radius is about half a square mile. The top 50 most densely populated cities according to Wikipedia all have over 20,000 people per half square mile, and that includes lots of European cities and even one in the United States:

http://en.wikipedia.org/wiki/List_of_cities_proper_by_popula...

As well as hundreds of local businesses who would pay quite a bit to advertise to them directly.

Right, but my point was if you are trying to find that one person 690 meters probably won't help much.

On the other hand, it says that 690 meters is the average. I wonder if the accuracy is higher or lower in more densely populated areas. My uneducated guess is that it would be higher and that you'd actually have a more accurate location for densely populated cities.

I think this is an amazing idea. On the upside it could allow people to micro-target services.

On the down-side it will allow people to micro-target without peoples permission.

Like anything this is a tool, that can either be used for good or evil. With great power comes great responsibility.

I think the service can become more accurate overtime as it establishes more known locations. Each known location could be used to determine the n+1.

How could micro-targeting be evil, besides the creep-factor?

I break into a site you use often and get a lot of personal information on you, but not enough; I can see approximately where you live, and go through your trash to finish up my collection (e.g., rifling through garbage to find SSNs, etc.)

If you look at my IP, I'm working in Delaware, but I'm actually sitting in Colorado Springs. It's not evil, but I'm not gonna be too happy if you advertise a "local" deal.

Geolocation using Wi-Fi BSSID/MAC addresses is probably more accurate and reliable.

WiGLE is a crowd-sourced database of the GPS positions of over 33M Wi-Fi BSSID/MAC addresses from around the world.

http://wigle.net/gps/gps/Map/onlinemap2/

oh god, so this means that because I'm hosting a VPS for some italian, they think that prgmr.com is in italy? it sounds like an even worse idea than looking at the address in the whois.