Sort of.
???
You could identify which ISP, a user had, but not the actual name of the uer. Most IP's given out are dynamic and without going to the ISP and getting info from them on which customer had which IP at what time, you couldn't tie that back to a specific actual person.
Not their real name, no. (Although a few years ago, this actually was possible with several major ISP's including Cox Communications.)
But I didn't say anything about their actual name. This example was a way to tie an IP and city of origin to a screenname. Most residential IP's are dynamic in theory, but in actual practice a person can have the same IP for many consecutive months.
If a person has leaked enough details about themselves over the years, (Age, sex, marital status, occupation, number of children, number and type of pets, hobbies, interests, type of vehicle etc) sometimes city of origin is all it takes for an armchair JW detective in the same city to make a damn good guess. If the person posts from both home and work, it gets even worse, because tying a commercial IP to a company domain is child's play.
I know of a JW that lurks here and makes a career out of this. (I'll PM you the name if you want.)
This doesn't mean anyone needs to stop posting. All it means is just like everything else on the internet, a little discretion is called for.