The biggest concern is that even if you are innocent, your data can and likely will at some point be used against you. This was proven by the Snowden Leaks. There are more than enough of these unfortunate cases, here are some examples:

https://www.phoenixnewtimes.com/news/google-geofence-location-data-avondale-wrongful-arrest-molina-gaeta-11426374

https://www.nytimes.com/2022/08/21/technology/google-surveillance-toddler-photo.html

I can recommend Privacy Guides, it's a website created by volunteers to teach people about digital privacy and security. It's great for beginners.

If you are interested in the topic, join !privacy@lemmy.ml.

There's no one-liner that will make the importance of privacy "click" for most people, since it requires a bit of abstract thought, but this site is the closest I've seen to it: https://www.socialcooling.com

If you want to do something about it, check out privacyguides.org, or the lemmy community (and instance) run by its owner, !privacyguides@lemmy.one

I'm sure there is a LOT of additional information about "what you can do", but here are some very simple starting points. You can do these today if you want.

1. Only use Firefox with uBlock Origin installed/active for web browsing.
2. Use a Virtual Private Network (VPN). https://protonvpn.com is considered one of the best.
3. Turn off location services on your phone (this will probably be controversial but I think it makes a lot of sense).

For more, subscribe to @privacy and read and support eff.org

Best wishes!

If you comply with their interests, nothing. Once you do anything that even looks like being against their interests, they use this data. There are programs of called DARPA LifeLog which literally logs everything. They even create DeepFakes based on the data they collect, ofc, not officially.

Yes, never give any data more than you need to give and move towards free and minimal software.

Alternatives

Besides what other people are saying, big data is a thing, sometimes there are correlations no one is aware of, but an unbiased algorithm finds. Let me give you two facts:

1. Insurance companies analyse personal history as well as general statistics when determining if they'll accept you and how much they'll charge you. e.g. a White middle aged man with some family history of heart problems will have a much higher price than a Black young woman without family history. This does not limit to insurance companies, banks can choose to not give you a loan based on any factors they choose, in fact any private business can do it.

2. Some of the companies that do big data can predict that you're pregnant even before you know it, just basing on random factors like search queries and email contents. Think about this for a moment, you don't know that you're pregnant, but because you searched certain terms (even if they're completely unrelated to pregnancy) a company can know it. This is also true of other stuff, but because currently this is used for ads there's not much reason to specialise this to find things like health or financial conditions.

It's not unlikely that in the future insurance companies could buy that data and use it as an extra point of data to give you a quote or to deny you entirely. And this would be something like In average, 90% of people living in NY who search for the price of a flight to Rome within a couple of days of sending an email with the words "cigarette" and "help" suffer a heart attack within 5 years, so because you're trying to help a friend quit his cigarette addiction and are planning to visit Rome your insurance just went up, because there is a 90% chance you'll have a heart attack within some years based on big data analysis.

Do you want to leave trace in your live, or will you disappear without a trace :v

...

From what I understand and not trying to read any of the answers to this.

For the large part of the picture, it's about marketing. To market specifically to you that is based on where you've been, what you've bought before and what your interests are. So they know that you don't want to buy or subscribe into things you've no interest in at any capacity. So why not try to goad you into it by using things you're into because of the data collected that's filtered from your interests?

That's probably the only not-so worrisome thing I can think of. It's just a giant distraction and tool to get you to spend and subscribe.

A lot of people don't like to be tracked and having data collected because, we feel it isn't anyone's business in what we do. So, why should it be the business of Google, Apple, Microsoft, Discord, Reddit, Facebook, Firefox .etc to be concerned in what we do?

Aside from marketing, it'd be a lot easier for all of them to pinpoint exactly what we do to feed data to authorities for easier prosecution. Which depends on how you look at it, I just think that if you don't want to attract the attention of authorities who've been given a tip on you without you knowing, don't be a criminal.

All in all really and I'm starting to derail my own explanation, it's a big wiry issue with privacy.

To put it plainly, it's largely for marketing and we really feel it isn't the business of corporations to know what we're doing, if we're knowingly not breaking any laws. Also now that I've thought of it, harvesting so much data increases risk of security breaches that hackers can take. Which means it's going from bad hands to worse off hands because now hackers can just sell our data around in the black market and we wouldn't even know it.

All my life I give up all my data to any product of any company I use. I accept all cookies to track me, send auto-reports and telemetry, try to join all beta products and gladly report bugs that occur. I use one nickname everywhere it is available, my home address and phone number and all social network pages are easily googlable, all my profiles are public. I always say what I think. I'm from Kyiv, Ukraine, and I have never had a single negative occasion due to my Internet behavior. AMA.

I used to care, but I gave in