When you post on reddit, instagram etc. you're giving the company your valuable data. (And it often is valuable, you put your thoughts into it and all that). Consider if you take 15 minutes to create value content, you'd get paid $5 or sth if you were doing it commercially. Now all that value is donated to big tech companies. (that's the only reason why they have value at all.)
So what's the problem with that? The problem is that reddit and others can instantaneously put your years-long effort behind a paywall. I'm not joking. Look at these:
when i want to see content on reddit (for research) or instagram (for local community) they don't allow me to see the data that users have contributed. Reddit claims that it blocks VPNs for "security reasons", meanwhile i'm using VPNs in browser's incognito mode to not be tracked. Instagram wants you to sign in sothat they amass more users and can take leverage of the network effect even more.
I can understand restricting who can post to limit bot activity, but reading must always be possible. After all, it's our data. That's exactly what happens when you give your data to big companies to "communicate with other people": your data becomes a source of income for them, at our expense.
VPNs prevent the site from attaching an IP address to the site visit, and incognito mode means that browser cookies routinely get scrapped.
While this is a popular selling point that VPN providers like to advertise, it's pretty misleading in terms of what this actually means with regards to tracking. Realistically, this does almost nothing to prevent sites from tracking you. They don't see you at your home IP as "John Smith" and see you on your VPN as "Hans Schneider", instead they see you at your home IP as "John Smith" and on your VPN as "still John Smith, but either traveling in Germany or using a European VPN".
Advertisers have tens of thousands of individual data points on nearly every single person who uses the internet at all for any purpose. All a VPN does is obfuscate ONE data point. That's less than 1% effectiveness at hiding your identity from advertisers. A VPN does basically nothing against all the other fingerprinting methods advertisers have.
Think of using a VPN like speaking into a walkie-talkie: your voice comes out at a different location, but if the person on the other end already knows what your voice sounds like, then they still know who you are, just not necessarily where you are. Unless you're taking other efforts to mask your voice, the walkie-talkie isn't protecting your identity in any way. Likewise with a VPN, if you go to the same sites from the same devices and log into the same accounts and otherwise engage in the same online behavior, the VPN is only hiding where you are, but it's still trivially easy for an advertiser to determine who you are.
This is a bit of a pet peeve of mine, because VPN providers harp on this idea so hard in their advertisements that it tricks people into thinking VPNs are capable of things that they just simply are not.
A few browser extensions can help with that further. UBlockOrigin, NoScripts, CanvasBlocker, Privacy Badger, Consent-O-Matic, etc. Maybe Decentraleyes but I don't fully understand that one yet.
Then there's DNS proxying and/or DoH, and a variety of other settings that can be tweaked for maximum privacy.
Any one of these things alone will leave holes, but putting them all together can significantly reduce your trackability and fingerprint. Of course it's a trade-off because some of these will break websites, but most allow granular exceptions so you can still use the sites you need.
In any case, a VPN is an important part of that, but the main purpose is to make it harder for your ISP to track you. Obscuring your IP from web hosts is just a bonus.
I think you are overestimating the capacity and will of advertisers to actually identify people like that. The data may be available for it in theory, but it's unlikely they built the systems to make it happen because they don't really have much economical interest to do so. They care about market segments, not individuals.
I had to work a bit on this kind of things. Most of those systems are really shitty and ineffective.
yeah i get your point but that's not what i meant. i'm using VPNs to do google searches, for example, in incognito browsing tab. so google knows the 10k searches i did, but it cannot connect them to each other, as session cookies between them are deleted each time i close the browser (which is about every few minutes). and i don't log in to any account in the incognito tab either, so it can't use account identities as fixed points either. and it cannot associate the queries by IP address either.
edit:
after seeing this website ... https://amiunique.org/fingerprint i get what you mean now. i have to think about this.
So how would one acquire the obfuscation they are seeking for? Making advertisers don't know who you are for everything you visit. Is it possible?
Uss the Librewolf browser. You need to turn off reduceFingerprinting and turn on WebGL to make some sites work, but even then if you go to CreepJS you will see that compared to Chrome, there is much less information like battery level, actual core/RAM count, etc for sites to use. And the browser has uBlock Origin to block ads and trackers, although turn off the Quick Fixes list as it might break YT bot protection and shadowban comments.
Not the OP you asked, but realisticly, your single best option is not giving any data. Use settings to prevent cross-site tracking in your browser where available, but really just post as little information as possible. The less you reveal, the less they will know.
Try this while on a VPN and in incognito mode: https://amiunique.org/fingerprint
I bet you'll be surprised at the methods companies use to fingerprint you - browser agent, Do Not Track enabled/disabled, timezone, screen size.. not accepting cookies is also a data point to filter you by.
wtf. why does my browser send such an uniquely identifying token. wtf
(there's more to the right of it, i cut it to preserve privacy)
WTF
TIL. the way trackers can do stuff
NoScripts and CanvasBlocker can help reduce your fingerprints.
Basically, most websites these days run javascript to harvest this info from your device. Sometimes they even integrate it into their basic functionality so that it breaks the site if you block it.
Opens your eyes quite a bit, heh? It's like you start seeing the matrix. Then you think of your friends and family, the "normies", and realize they have zero chance. We have all become a cog in this advertising machine.