Re: Look at the bigger picture
This is a somewhat lengthy ramble, forgive me if it’s not your cup of tea - please ignore me, rather than downvote me! :-)
In my preceding post (see above) I commented “we aim to lose by the smallest possible margin” which recognised that total privacy is unrealistic, short of unplugging from the internet (and throwing your mobile away)
Additionally everyone has their own level of paranoia (as you might have gathered mine is high - must keep on taking them pills) however I recognise that people are different and may decide the perceived risks do not justify the expense/effort. People lead busy lives and teenagers can be very demanding - why is tiktok not working!
My (somewhat) amateur setup comprises a Pfsense CE firewall (yes, I know, I don’t like the direction that Netgate are going with it) but crucially it incorporates the pfblockerNG third party package. It's this package that keeps me on Pfsense rather than exploring alternatives like OPNsense.
With pfblockerNG it’s possible to automatically create firewall rules to not only block sites based upon DNS lookup (I describe it as a PiHole on steroids) e.g. so adding via online blocklists and bespoke entries, but also block whole IP subnets et al based on ASN (i.e. IP ranges)
This is a very powerful feature as it (normally) defeats hard coded IP addresses in applications that attempt to bypass DNS blocking (both inbound and outbound)
However this approach does (unsurprisingly) break things - for example you find that portions of iCloud are hosted not on Apple infrastructure but sometimes with competitors! CDN’s are widely used with big players e.g. AWS so this can cause “issues”
So for instance, by default I block all ASN’s associated with
Facebook
Google
Microsoft
Adobe
and many others
and then create firewall aliases to allow access for certain network devices to access certain ASN’s. The control can be quite granular. As an example I run my own private (cough, cough) Invidious instance, but this is hosted on its own raspberry Pi that is allowed access to Google ASN’s but then proxies the service to devices on my local network, so this means by default Google is not enabled network wide.
Routing my personal devices back through my home network via VPN allows me to maintain the benefit of this infrastructure even when out and about on 4/5G (yes I know Apple and iOS seems a bit flaky as regards killing the connection when/if unexpectedly the VPN drops)
I should add that I also run a separate DMZ network for untrusted devices that need internet access to work - e.g. Tesla Powerwall gateway but these are fire-walled off from my trusted network. This approach allows me to use Hikvision cameras (which seem very good) but they are not allowed external access to the internet, so that stops any potential for phoning home.
The cat is truly out of the bag as regards privacy, there is no ultimate solution, only damage limitation. Mitigating steps to consider (forgive me if I am preaching to the converted)
If you don’t provide the information in the first place to a third party it’s difficult for you to be exposed to hacking et al.
Email aliases are your friend (so when the spam arrives, you know who sold out or has been hacked) It also allows one to delete the alias and the spam problem goes away.
Password managers - use one, but self host your data (not “in the cloud”)
Encrypt all data not stored on your directly controlled devices (and also key data “in house”) and ensure you control the access keys (i.e. not managed by the third party provider)
Give the barest information necessary - online shopping, don't tell them your forename, initial only. Don't specify your sex (another contentious subject these cays!) Why do they want a phone number - they got your email (so if mandatory field use 01234567890)
Of course this approach does not work for those bodies that require your detailed data - be it for credit checking (damn there goes my date of birth) or official purposes (I seem to recall the voters roll data at a national level was hacked some years ago) DVLA, NHS and the like are impossible to protect yourself from. BTW did your (dentist/health provider et al) ever ask you if it was okay to store your data “in the cloud” or did it just sort of just happen?
Run your own fully resolving DNS server so you are going to authoritative source (and whilst at it) route outbound traffic via a trusted VPN provider (yes I know another can of worms requiring careful investigation)
I could go on, but you get my drift … and well done on making it this far.
Ps my most hated expression
“Your security of your data is of the utmost importance to us” <add relevant hacked company name here>