Discourse Fingerprint comes as a tool to community managers in their combat with internet trolls. :troll: 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 relatively small number of user agents, screen resolutions, etc. However when you take into all of these 20 factors, there is a very small chance that two users will have same key.