>>983256
There are free and paid API.

This is free that you could use to create a know list of companies who offer their services as a proxy or VPN
https://ipinfo.io/lite

Then pull other feeds updated classified as a VPN or abusive like this random example
https://github.com/az0/vpn_ip
Or just use that.

It's not difficult and would integrate into existing feature on boards to block posters from VPNs / proxies.

It could be one python script that is scheduled to run everyday.