Everyone knows your location: tracking myself down through in-app ads

One big privacy issue is that there is no sane way to protect your contact details from being sold, regardless of what you do.

As soon as your cousin clicks "Yes, I would like to share the entire contents of my contacts with you" when they launch TikTok your name, phone number, email etc are all in the crowd.

And I buy this stuff. Every time I need customer service and I'm getting stonewalled I just go onto a marketplace, find an exec and buy their details for pennies and call them up on their cellphone. (this is usually successful, but can backfire badly -- CashApp terminated my account for this shenanigans)

>One big privacy issue is that there is no sane way to protect your contact details from being sold, regardless of what you do.

>As soon as your cousin clicks "Yes, I would like to share the entire contents of my contacts with you" when they launch TikTok your name, phone number, email etc are all in the crowd.

Fortunately this is changing with iOS 18 with "limited contacts" sharing.

https://mobiledevmemo.com/wp-content/uploads/2024/09/image.p...

The interface also seems specifically designed to push people to allow only a subset of contacts, rather than blindly clicking "allow all".

The far bigger issue is the contact info you share with online retailers. Scraping contact info through apps is very visible, drawing flak from the media and consumers. Most of the time all you get is a name (could be a nickname), and maybe some combination of phone/email/address, depending on how diligent the person in filling out all the fields. On the other hand placing any sort of order online requires you to provide your full name, address, phone number, and email address. You can also be reasonably certain that they're all accurate, because they're plausibly required for delivery/billing purposes. Such data can also be surreptitiously fed to data brokers behind the scenes, without an obvious "tiktok would like access to your contacts" modal.

People will share their whole list because it’s simpler

Or because they were tricked. eg. LinkedIn’s “Connect with your contacts” onboarding step which sounds like it’ll check your contacts against existing LinkedIn users but actually spam invites anyone on your contact list that doesn’t have an account.

Linkedin is so terribly evil these days.

I also see the shenanigans of adding new 'privacy' settings and setting them open by default. Another typical Microsoft ploy by the way.

They were evil before.

Previously they’d take your LinkedIn password and try using that to log in to your email account to grab your contacts.