If i pull up to a red light beside somebody playing with there phone i usually blow the horn. When i get there attention i'll mouth with my hand on the side of my helmet like holding a phone and tell them "GET OFF THE F__ING PHONE!" About 90% of the time they will put it down. I had one guy roll his window down and yelled "What you said?" I said it loud enough so he could here me. "GET OFF THE F__ING PHONE!" By the time the light changed , i'm gone and the person behind him was sitting on the horn blaring away.