Google Voice has a similar screening service. From the GV help forum ...
"when call screening is enabled:
If the caller's name and phone number are in your Google Contacts, or the caller is a business known to Google (e.g. it shows up in Google Maps with an information box), then that name will be played to you. If the caller's number is not in either of those places, then their calls will be screened every time, until/unless you add them to Contacts."
"when call screening is enabled:
If the caller's name and phone number are in your Google Contacts, or the caller is a business known to Google (e.g. it shows up in Google Maps with an information box), then that name will be played to you. If the caller's number is not in either of those places, then their calls will be screened every time, until/unless you add them to Contacts."