I've been coding for over 20 years now! (WOAH, do I feel old)
I've touched just about every resource imaginable under the Sun (too bad they were bought out by Oracle)
I'm going to tell you the absolute scariest thing about GeoIP looking. The public databases are intentionally low quality. While not true of EVERY IP address, there are ranges (very large ranges, like /16s) where virtually every address can be identified to within under 100ft. Yes, that accurate. Yes, I know this, because I was the one that discovered an exploit in a particular ISP's handling of information and published the finding some years ago on this topic. I wont repeat it now, because of how dangerous that information is, but these types of highly accurate databases do indeed exist.
I'm going to tell you the absolute scariest thing about GeoIP looking. The public databases are intentionally low quality. While not true of EVERY IP address, there are ranges (very large ranges, like /16s) where virtually every address can be identified to within under 100ft. Yes, that accurate. Yes, I know this, because I was the one that discovered an exploit in a particular ISP's handling of information and published the finding some years ago on this topic. I wont repeat it now, because of how dangerous that information is, but these types of highly accurate databases do indeed exist.
Thanks for sharing Vincent.