Mobiles again

Driving home about 2pm today (Friday) - and its quite busy on one of the main roads in the city.

Theres a small roundabout (not like the ones painted on the ground, it has a wall but its not a mbuttive one) - anyway its almost totally jam packed. I take my exit which leads onto a long road which is at a stand still.

I notice the girl behind me is looking down at something, I buttume its a mobile as she looks like she is reading and then laughing, and at other times it definitley looks like she is doing some texting...

Not really a major problem IMO as the traffic is moving slowly and not at all sometimes. However when the lights change and I move forward about 10-15metres she still has her head down so doesnt realise I have moved forward so much.......probably wouldnt be a problem on a non busy day but as she is not moving she is still causing cars stop be still all the way back to the roundabout.

This happens loads of times (at least 5) over the course of the same road, I cant believe she would be looking down at her phone so much that she doesn't even relise the traffic is moving on ahead... oh well, she didnt get any beeps (i probably would have if i was behind her - not long ones, just a quicky)