I am a lawyer that has filed a lawsuit against an adware company on behalf of Illinois residents. My understanding is that the adware company collects ip address information, which can be used to help identify which state a person lives in. What tells you that a computer ip address is from Illinois. Is there a specific # in the IP address? Is there anything better than IP addresses to rely on? Also, is there an efficient way to process hundreds of thousands of ip addresses to determine which are from which state. please email me: [email protected]
There are a number of different measures to tell if an IP address is from a particular area - traceroutes, whois, hostip.info's database, or any other ip-location database.
Quite a few users on the internet now (Cable, DSL) are automatically assigned an IP address when they connect. These are selected out of a pool of many which may be assigned to a particular local area (DHCP) or for the providers entire coverage area. If this is the case, it makes it difficult to always determine the exact location.
However, it *is* trivial to determine the country someone is in based on IP. It's also relatively easy to determine state (in US), but anything closer than that needs to be done with some sort of ip-location mapping (such as the database we have here) - or to use traceroute or something similar...
Hope this helps