Discourse check the user IP for block list only on login

[Canapin (Coin-coin le Canapin)]

Maybe this?

Discourse Fingerprint - Browser Fingerprinting Plugin

Discourse Fingerprint Discourse Fingerprint comes as a tool to community managers in their combat with internet trolls. It works by computing a unique identifier (a fingerprint) of each registered user, by taking into consideration over 20 browser characteristics such as user agent, screen resolution, timezone, device memory, etc. When each of these browser characteristics are considered separately, they are not enough to assess whether two users are the same. There is a re…