Since I've started commuting with a bike I've been paying more attention than I did with a car. I have noticed a lot of people using mobiles while driving. That's not to say I haven't seem them while driving, it's just that I've been more alert and it's shocking how many people are on them. Sadly it's mostly young drivers and have also noticed considerably more females. Tempted to sound the horn while staring them out (at the lights in particular) but I'm not that agro. There's also the concern of road rage...! And I understand it's not the public's job to police stuff like this but... Do you beep your horn at them or just stay clear?