Bothers me? Somewhat.
But it's not only FB that does it. Pretty much if you use the internet, it's going to happen.
How that works out in practice, for me, is not a problem at all. I don't randomly surf, I keep a tight control of my FB news feed, I use ad blockers, and I am really good at ignoring ads when I do see them.
And the system can be manipulated. It's easy enough to visit an online pet supply, an online book store, or something innocuous, click around for a minute, and that will shape my ads for weeks or months.
But you really can't use ANY online sites without this happening. And it's easy to see the effect of. Just once visit something with high online ad frequency (medical needs are a good bet) and then see what happens to your web experience every place you visit.
It's not FB's fault (who I don't visit that often and never click on ads from) ... it's the INTERNET at large that is to blame.
My personal behavior is extremely innocuous, so they aren't going to get anything more condemning on me than the fact that I'm a Christian, which I don't hide anyway, or my profession, which is almost public knowledge.
But yes, it's a terrible invasion of privacy IMO. Just not one that happens to damage me personally, so for me I will continue to use the internet the same as I do now.
I realise it's perhaps a tad off topic, but I'll reply anyway.
You are half correct. You don't need to use facebook for this to happen. Indeed, you go to a website with ads, and it will show you ads based on surfing history. And depending on if "they" have access to it, also your mailing history.
You are wrong however, that this is just how "the internet" works. It is not.
It's how
online advertising works. Online advertising is largely in the hands of 2 companies: google and facebook.
When you go to website X that has ads, it's not website X that's keeping track of your data. It's the google/facebook plugin included on that website that does that. If you are not logged in to google / facebook at the time of surfing, the data is saved in a profile with a hardware / browser id. Once you log in on goolge/FB with that device, the anonymous hardware/browser profile is linked to your google/FB accoun.
This is how these companies build "super profiles" on you.
They know what your accounts are, which devices you use, which websites you frequent at what time of the day, who your contacts are, what you are mailing about, etc.
I agree there is no escaping, currently.
Precisely because it is all done "in the background" with the use of server-side plugins and client side cookies. And all that,
without explicit consent of the user.
In Belgium, FB was called out on it. On websites that use a FB plugin (typically the thumbs up button), they treated both FB users and non-user in the exact same way, while only FB users had agreed to their terms of service. So they were forced to stop collecting info from non-FB-users. They said that "it couldn't be done" without blocking all "public" FB features (= ability to see public pages without logging in). Belgian authorities persisted and as a result, FB simply blocked all public FB features in Belgium. Now, it is impossible to see a publnic post or moveclip or whatever. All pubic content viewing (and data gathering) now requires being logged into FB. They thought such a move would cause belgium to back down, but luckily they did not. They accepted this "solution" and now they are stuck with it, lol.
Anyhow, to summarize: no, this is not how "the internet" works. Instead, it is how FB and Google's advertising business works.