The best way to stop cell phone usage

Actual thing that happened last week:

The light rail train I take travels down the median of a main boulevard and then crosses over the southbound lanes and a crosswalk to head northwest. One morning as the train was waiting at that intersection the operator used the external loud speaker (which we on the train all could hear as well) to say to someone the following:  "You need to get your behind off the phone!"

I couldn't see from the second car to whom she addressed that order, but presumably someone was lollygagging on the tracks with a cell phone to his/her ear, oblivious to the large train waiting to go.

I may have to look into becoming a train operator just for that reason. How awesome would it be to blare a verbal ass-whooping with tons of steel to back you up?