Same IP address(es), same OS/browser/app, same configuration? Easy match.

I mean, they got me, that's for sure. I used to cycle accounts pretty frequently to dodge stalkers, but even a dedicated user could've figured me out just by matching the different subs I posted to. I eventually stopped posting in my local subreddits because of this, but even so, I talked about a lot of seemingly-common things that in aggregate could identify me pretty accurately. And that's even without the data that only Reddit admins would have access to, like browser fingerprinting and whatever tracking mechanisms I wasn't able to block (or the mere fact that I did block them).

For example, millions of people use the same phone model as I do, but how many of those also share my hobbies? How many of those play the same types of games? And how many of those use my same general writing style? How many times did I throw in an idle comment referring to a city I'd traveled to, or hinted at where I grew up? Oh my god, did I call Coke "soda"?! Information is leaking everywhere!

Heck, I wouldn't be shocked if someone could match my Lemmy account to my Reddit account(s). It'd take a crazy stalker with a lot of time and skill, but with the ever-increasing power of AI, it'll probably be easy for any schmuck to do within a couple years, never mind major governments and corporations. There's a ton of information that's hidden in plain sight, and it won't stay hidden forever.

Man, if I started getting nsfw recommendations on my sfw account, I'd be pissed. What else could he even want to practically/legally use that info for?