I need to figure out how to start deleting account that don't use this technology. Right now I have over two hundred entries in my keychain for passwords alone. While these are all unique passwords they still do not offer the security that Sign on with Apple does. Everything I can migrate to the Sign on with Apple is a win, not just because of privacy, but also the two factor authentication.
I started going through this process myself. A really good place to start is your Facebook apps & websites page.
Here’s a shortcut:
https://www.facebook.com/settings?tab=applications
In there, I found dozens and dozens of sites and apps I had previously logged into, including sites I had never really used more than once. Deleting your connection to these apps via Facebook almost always deleted my account on that site or at least deactivated the account.
The next place you can check is which apps and sites are sending you emails or at least sent you an email when you signed up. I created a search filter to show me only emails from addresses
not in my contact list. I still got a ton of entries so I narrowed it down by adding “Welcome” in the body of the email to my search. You’ll be surprised how many websites say that when you sign up.
The process from that point was more manual. I went to each site and looked through their settings to delete my account. If I wanted to keep the site, I created an email address just for that site. Because I have an email server, all my email addresses for logging into sites look the same except for the site name:
macrumours@mydomain.com,
eBay@mydomain.com,
ubereats@mydomain.com, etc. All these emails are sent to my real address. If I ever want to kill one, I can do that without it affecting the others.
The last step will be to sort through my Keychain. I’m going to wait until April when most apps and sites I’m using are working with Sign In With Apple. Everything else will either get the unique email treatment or deleted.
There are other ways you can be tracked but Apple seems to be doing a good job of killing those tracking methods in Safari.