> cars

Good example: cars come with a tracking identifier (license plate), tied to a responsible individual, who is subject to a test, and whose permission to use it can be revoked if they abuse it badly enough.

While there are more trolls and bots on Facebook than real users, but many of those real users have no issue using their real name and picture while excepting awful behaviour. I'm not sure that adding an identifier is really going to help that much.

Yes, that's why we should deanonymizing the internet. Everyone should need a government-issued license to access websites. That's exactly what the modern society needs. (in case it's not super obvious, /s)