Understand that it's fetching the data from the system's address book, but obviously this is going to be the same data it would remember if you entered it elsew

Understand that it's fetching the data from the system's address book, but obviously this is going to be the same data it would remember if you entered it elsewhere. Keep in mind that this is a feature of Safari being exploited, it's not like this is an vulnerability in the address book gives you unlimited access to all the user's contacts.