I have watched people drift out of their lane and run lights and so on while holding that phone against their head. I have had to honk at them while slamming on the brakes because they decided to pull into my lane without looking to see if I was already there. I have wished that someone would take that damn phone away from them so they could drive without crashing into me!
I have had to do this to people who weren't holding phones to their head... more times than I care to count... it happens whether people talk on a phone or not.
It's even worse when on my motorcycle.
If a driver isn't paying attention anyway, it doesn't matter if they are talking on the phone or not.
It is easier to write an incorrect program than understand a correct one.