I don't notice whether they're on the phone or not. It makes no difference to me, as I'm just looking for what might happen. Whether they're on the phone or not is irrelevant. Everybody out there is stupid, careless, and inattentive, and it's my job to keep them from killing me.
(BTW, that is not an attitude I adopted when I started riding. It's what I've known since I was 16 and started driving.)
Had a bread truck pull across my lane to start a u-turn the other day. Horn, brakes, stopped OK. He stopped, looked, saw me and finished his turn! This made me realize the advantage the AE riders have. With a fist full of brake and another full of clutch, I had no gesturing digits free!
Cool thing about bread trucks, though, is they have a vehicle number and company name. Complaint filed.