I understand it's a criminal offence but would you be happy dobbing someone in and they then lose their livelihood thanks to you?
Flip it around. How would you feel if you didn't report the person and then read they'd gone on to kill someone while on their phone?
"Dobbing someone in"? Are we supposed to look the other way because it's not OK to report someone in a kind of prison/playground rules mentality? Does the same apply if the driver is clearly drunk behind the wheel?
I'd feel fine personally. In the last month, I've seen numerous drivers on their phones while moving; a delivery driver nearly reversed into me (also threatened to kill me in the exchange we had about him being on his phone) and a cabbie cut across me in traffic. Neither were aware of me because neither was concentrating on driving. If not for my actions in avoiding them, I'd have had two pretty nasty accidents; both because of two morons that thought their usage of a phone was more important than the lives of pedestrians, cyclists, and fellow drivers.
If that person cared about keeping their job, they wouldn't chance being caught on their phone when driving. There's no excuse to be on it when driving. EVER. It is THEIR action that's cost them their employment, not mine.