A simple phone thought

Thought Trigger:
An anonymous phone call on a sleepy Saturday morning

Thought:
Why do phone companies relay only the telephone number to your cell phones? Why don’t they send both the number and the registered name of the person or organization?
This way if you have not set an alias for that number in your address book or the number is anonymous, the phone will display registered name.

Imagine life if something like this would flash on your screen as it rings:

1. AT&T Customer Service
2. AT&T Late Payment
3. Payphone on 1st street, San Jose, CA
4. Telemarketer - InsuranceCompany
5. Mr John Stevenson

Advantage:

1. Makes life easier for late sleepers and sleep catchers
2. Helps call screening. There may be 1 in 100 anonymous calls that you would want to answer immediately, 10 in 100 later and 89 in 100 never. Don’t confuse this with the telemarketers because you can always use the government mandate of “Do-Not-Disturb” or “Do-Not-Call” feature of your service provider

Disadvantage:

1. I can hardly think of any

What technical difficulty could the implementation of this have that can’t be overcome?