Well, it's not the cell phone (iPhone or Android) that is doing the spam ID, it's a service being queried as the phone call is being placed. Something like, Al

Well, it's not the cell phone (iPhone or Android) that is doing the spam ID, it's a service being queried as the phone call is being placed. Something like, Alice (the originator) calls Bob (the terminator). Just before the phone network causes Bob's phone to ring, it requests (via the network) a service that says "classify the originating number" and that service might return both a name "Alice" and some form of reputation (like "normal" or "potential spam") which then gets sent to the phone that causes it to start ringing (I know, because I worked at a company providing such information). What I found works for me is to assign "silence" as the default ring tone, and give each of my contacts a non-default ring tone. If someone not in my contact list calls me, they can leave a voice mail message. Yes, it means I might miss a critical "deal with me now" call, but that's a chance I'm taking.