I think there are many more categories. I am on Twitter with a pseudonym, and while it is not bot-looking, it is obviously not a real name. At first glance I may or may not be a bot run by somebody else. I can be Googled easily and you will find some PII there, such as my employer, but it would take some checking that you can't scale.
I am definitely between 2 and 3 in the above classification, and so are many of my contacts I would say.
I am definitely between 2 and 3 in the above classification, and so are many of my contacts I would say.
[edit: can't* scale]