This is anecdotal, for now, but I can personally confirm that all your online accounts are linked to one another and whatever network that oversees them makes calculated moves depending on what you do on them.
Let me explain.
I've had a YouTube account for a while, we'll call this accountA. When I started work about 4-5 years ago I made a separate one, accountB, on a different e-mail address so they were completely unconnected purely for work purposes, like listening to music/podcasts and looking up photoshop and programming tutorials for work.
After a while, they started to blend together with similar recommended videos, but it doesn't stop there.
Say I watch something on accountA at home. When I get into work the next morning I'm surprised to see nearly all the same videos I watched the night before in my recommended video list on accountB. This isn't a one-time thing. This is pretty consistent.
Likewise, the same happens in the reverse. I'd tested it by taking up a hobby of tying knots. I'd set up a couple knot videos at work and listen to them while working. After a while, the same merging scenario started to happen. Now both accounts are recommending knot videos, but like I said before, they are now recommending the exact same videos that the previous account had already watched, with little to no delineation.
There are other instances of recommended videos that follow suit. At this point the accounts' recommended pages are almost 1:1, despite me typically viewing completely different content on them throughout the day. Somehow, YouTube/Google knows I'm the same person operating both accounts.
I've only just begun to catalogue the nature of these accounts, so bear with me on the lack of specifics. It is more than just a hunch or gut feeling. I'm pretty sure at this point that social media sites can easily pair accounts to one another and act upon that data.
I'm not sure it is worth following up on, but just so you know...
If you're using the same wifi router then they can use your router info to link accounts... a couple of weeks ago my wife started getting solicitations for emergency food on her work computer... I told her that I've been using my work computer to look at buying emergency food... we both work from home and use the same wifi router
Nope. Completely different locations.
I use headphones, so I doubt that.
I also use an iPhone 5s because of the hard-coded planned obsolescence in anything past 6s.
I doubt they would bother developing any snoopers on something so old at this point.
I have another example. You know how if you mention a product out loud that your FB feed will suddenly start showing ads for it? I was recently working in a setting where most of us didn't keep our phones on our persons. Once in a great while we'd show each other a pic on our phones in passing in the break room. So when I started seeing ads for a craft another person at work is doing on my FB I started trying to figure out where they were coming from. At first I thought it might be because my daughter and I had discussed it. But then an ad for the company that this person's husband works for appeared on my FB. I had no other association and had never uttered the name myself. I figure it's happening via the free wifi at work. All those stores offering free wifi so you'll use their app while you are shopping? Prob using the apps to spy. It might even be happening while our phones are in our lockers in close proximity. Think about it.
I have two phones now. One I leave at home because it dies if unplugged. Another phone with another number that I carry for texts and calls. Zero apps on it, leave blue tooth OFF and WiFi OFF most of the time. Keep cameras covered. Not even email on the 2nd phone. Both with cheap service from different carriers.
This happens to me and my fiance, we both have seprate phone accounts, but live together, the videos I watch show up in his recommended feed, I noticed because I watch this guy called Lamont at large, it's an obscure channel, the guy visits unique graves, and famous resting places, one day he was telling me he found a channel he thought I'd like, turns out I was getting recommendations for Cleetus Mcfarland videos, and that was his favorite. Same thing with various other channels.
The link is your browser.
If you view those videos via web browser as logged-in user, they are in browser history. E.g., with Chrome, you see the same bookmarks, history etc. in your home computer, work computer, tab, smartphone, they are constantly synced (and saved to Google database with your passwords and everything you ever type in your browser). I started using browser login because at work, our workstations were changed almost daily, and it's annoying to come every day hour early just to check if you have everything needed for your shift, or have to start clean setup, import etc. Duckduckgo extension can help a bit while avoiding tracking cookies, but history itself remains.
This. This is the correct answer, handshake FTW.
Cookies and Advertising ID on mobile devices. It's not AI, and it's nothing new.
You said you used two different computers with different accounts on each.
What operating system are you using?
Windows 10 I presume?
Did you buy both copies of Windows 10 using the same account, or even the same credit card?
If so, they are linked and they share everything, even if you don't intend them to.
Windows watches you like nothing else in the world. It's one of the most invasive pieces of software you have in your home.
One is Windows 10 the other is Windows 7.
Neither have any connection to one another, as one is purchased through work and the other is old as dirt and purchased by cash when Windows 7 came out.
A lot of websites have frontend trackers that can be identified and stopped, but they can do all that and more server side. Almost all large companies are going to sell all of the data they can to make more money. They will correlate everything possible. ISPs can harvest and sell data as well. Is it legal? It doesn’t matter when they make more money doing illegal stuff than they will pay out when they are caught.
I use brave on both, but I've not registered an account with Brave.
Unless Brave is compromised, which it may be, I sure hope they aren't linking through that avenue.
Tech companies buy and sell user data between each other. This is probably a consequence of algorithms cross referencing the data bases.
Ignoring all the obvious backdoor data sharing deals going on, modern data analysis enables identification of users provided enough data.
All sorts of details go into estimating who you are in between platforms, from the way you use your mouse, move around geographically, your active times and durations, and any of your general browsing or other measurable habits add data.
As soon as you use a compromised (non-anonymous) exit or combine your VPN with anything identifying (e.g. credit card payments) the probability of you being found increases drastically.
If you really want privacy you'll have to go out of your way to mask your behavior by creating multiple identities.
I guess what I'm trying to say, is that I did this and it didn't matter. They still figured it out despite all my attempts to stay separate.
I've been aware they can link accounts for years now. This goes far past what I thought possible without individually targeting a person. Basically, they've made absolutely sure that their are accurate in automatically linking accounts beyond what should be possible on paper.
They've dedicated that much time to it.
Unless you use different phones with different providers, VPNs and maybe even names they'll find out.
Another aspect to consider is that even if they don't manage to pinpoint the individual they can estimate your behavior based on thousands of people who behave in similar ways as you do. Humans follow remarkably close patterns if you manage to match individual with (not necessarily geographically or otherwise related) group.
The things we can do with statistics these days are truly mind boggling.
Are you using Gmail accounts to set up the YT? That's the link.
No, they are yahoo accounts. I set one up before Gmail was even a thing, if you can believe it.
In addition, I've never logged into either account on any computer other than the computer I use them on, so no cross-over there.
First time? . . . . I wish I could post the pic that goes with it.
so they could actually track down all those antifa people if they really wanted to. but we know they dont.
Unless you are on your own DNS or using DNS TLS to Quad9 everything you type into your browser is getting sent in plain text and sold by ISPs to big tech.
This isn’t hard to do.
Variety of methods to track you and build a profile. The longer it goes on the more your ‘profiles’ could merge.
Cookies, 1 pixel trackers, location awareness, etc.
Google is evil-smart. Your brower is Chrome? Maybe your phone is Android?
It's ubiquitous. I called to schedule a GYN appointment using my landline. Cell phone was in a completely different room. Logged onto FB and the first ad that pops up is from Wish . com advertising a speculum! Why in earth would anyone want to buy one of those and how in the eff did the conversation get tracked?!