i know how: you need a verified phone number to open an account, and open ai does not accept chinese phone numbers or known IP phone numbers like google voice.

they also block a lot of data center IP addresses, so if you're trying to access chatgpt from a VPN running on blacklisted datacenter IP range (a lot of VPN services or common cloud providers that people use to set up their own private VPNs are blacklisted), then it tells you it can't access the site and "If you are using a VPN, try turning it off."

OpenAI requires a working phone number to sign up, and a credit card to use various features.

So they just block the phone numbers (which has a country code), and credit cards (which owner/issuer's country info is available).

Not sure why this seems to be such a surprise to everyone here...