alt Hacker News> My only solution that I could think of is to have a dedicated phone line just for friends/family/work, and a second line for banking/shopping/utilities/everything else.
This fails the moment one of your "clean line" contacts downloads a sketchy app that sells all their contacts, and sells an updated list as your appear in their recent calls list - meaning it's not a one-time thing, it's for a few weeks after every time you call them.
It works if you only allow incoming calls from your contacts (e.g. whitelisted numbers) on friends/family/work line. If that number leaks, who cares? The random numbers will be blocked anyway. Probably would want to set it up so the 'public' line is silenced - just periodically check the VM box for anything important.