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[paul at clubi.ie]

On Mon, 20 Nov 2006, Dave O Connor wrote:

> Geolocation is pretty accurate these days, certainly to the city 
> level. Any web service can tell who you are to the city level 
> pretty accurately without any prior information.

That's bull, sorry. I was with you on "pretty accurate", but you lost 
me with the claim in the second sentence. Geo-location might 
correlate "pretty accurate(ly)"  with end-user location across a 
large sample of addresses, however, for any given IP you just can't 
tell where the end-user is, sorry.

- The IP range may have a very wide geo-graphic useage, despite some
   some specific attribution in registrar records..
- The end-user may not be located at the IP address you see
    - caches
    - VPNs

FWIW, of the 3 or 4 networks I use, only 1 gets geo-located to 
city-level at all accurately, according to 
http://www.geobytes.com/IpLocator.htm anyway.

   - boron.eu.sun.com apparently is located in Washington DC, despite
     the clue in the hostname.
     - the VPN and/or corporate caches case
   - use another network and apparently I'm in London
     - the 'network allocation that is used across a wide geographic
       area' case

The only one which gets me "right" are one network which is pretty 
tied to a certain city for quite obvious reasons, and another network 
for which I filled in the whois for the assignment (if it weren't for 
that, geo-IP thingies would have me in Dublin, where the delegating 
ISP is, regardless of where I was in Ireland), so it doesn't count - 
I could fill anything in I wanted.

So sorry but your claim is quite wrong, at least to "can tell who 
/you/ are" granularity...

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
Booker's Law:
 	An ounce of application is worth a ton of abstraction.