Today around 12:00pm EDT, a post was uploaded to r/whenthe by u/concussionmaker_91 about how despite their multiple privacy measures, Reddit was still able to ping their location and show them an ad about a business in close proximity to their house. Then, in less than 2 hours after the post when live, their year old account was permanently banned. 
Redditors in the comment section used a website called SnooSnoop to see if this account has done anything malicious in the past that may be grounds for a ban only to find nothing. 
I don’t think this is a mere coincidence and some comments I read on the post may be there to dismiss the situation.
I’m currently working on archiving the post and comments in case Reddit decides to try and erase this entire situation from the web, I’ll attach the files when I do.
Two parts to this:
The first is Reddit (or any site) being able to identify you. And that is not a hard problem. Either they fingerprint the browser so your cookies tell who you really are or they just analyze your traffic and realize this user in Istanbul is constantly looking at the Cleveland subreddit. Its why VPNs aren’t really (at all) useful for privacy unless you are combining it with burner accounts and even browsers. VPNs mostly are just useful for accessing region/network limited resources and spinning up a true beater.
As for the ban? They probably changed VPN, got an IP that a known “bad” user used, and got immediately caught in the same automated banwave. Don’t use VPNs with accounts you actually care about. Partially because of the risk of data leakage but also because you don’t know what the last person using that IP did. See also why you wear a condom before you stick it in the glory hole.
See also: why you don’t wear a condom someone else came in