Forum Moderators: phranque
Geolocation is fundamentally flawed. Especially so for AOL users.
AOL's proxy server (and other proxy servers) hide the IP address of the user. Unless AOL has inserted some non-standard header with a more localized IP address or other location information, there's nothing you can do.
You might want to examine headers to see if there is something useful there. I doubt it.
One anti-fraud company claimed to have a solution, but has backed-off on their claims. They simply identify AOL users as such. (e.g. "this is an AOL user...")