Re:Apple apps on Big Sur bypass some firewalls and VPNs
by gcoleman on Monday November 16, 2020 @10:47AM
(#25113074)
Many geo-ip services also offer VPN or server detection (e.g. is the IP in one of the EC2 ranges).
In a previous job at an online gambling company we found that a large percentage of fraudulent user accounts came from VPNs so ended up banning them at the geo lookup stage.
And for sites with a lot of traffic, you probably don't even need an external subscription, you can deduce the ranges yourself simply by checking for IP addresses that wind up having logged-in users from all over the world in a short time frame.
Pretty easy to do accurately with a short set of heuristics.