My Info Blog My Sister's Physical Location (city) Was Tracked After She Posted On An Online Blog. How'd They Get The Info?

My sister's physical location (city) was tracked after she posted on an online blog. How'd they get the info? - my info blog

My sister posted a blog online blog forum. Then someone had the data, saw a strange combination of letters and numbers on the blog itself [show has info] and disclosure of your city and country on the blog. Who knows how much they have? How did they learn and what you can do about it?