Where does FaceTime get your contacts from?

This is on a mac, not an iPhone. I rarely use FaceTime but I went to call a friend. When I went to my contacts list, it has a whole bunch of people listed. I know all these people but most of them not well at all. I thought it was from my phone, but some of the people, I've never had in my contact list before. And some who were, were not on the list. My high school chemistry teacher is even on there. I'm super confused haha.

Your mac syncs the contacts you have on any device when you log in with your apple id. It got them from your phone or another device (like an iPad?) I believe it also has the ability to sync from Facebook and your email.

Either your phone contacts (if you've ever plugged one in) or your email contacts - ever emailed your chemistry teacher about homework or something? That'll be why the address is on there.

Open Address Book. Any contacts there? When you use AppleID on more than one device, such as also on your iPhone, the contacts are combined.

Apple Mail also syncs contacts to FaceTime from all the email addresses there. Annoyed? I would be also, but the only recourse is to send feedback to Apple to allow unsynced, full user chosen contacts. That will probably happen in the year… No.