Understanding Reddit's Use of Browser Fingerprinting

I was browsing reddit in Firefox with no account signed in and with my browser configured to auto-clean all browsing data upon exit. I looked at a few posts and comment sections

The next day I went to reddit again. This would have been with a totally "fresh" browsing session in Firefox with no cookies or browsing data from the day before. When I went to the same subreddits as the day before, I noticed updates beside the comment counts …

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