That might seem self-evident, but texting while driving has become a major cause of road traffic collisions, and other major incidents, involving pedestrians and others.
AT&T have sponsored a new documentary movie (directed by Werner Herzog), which you can see on youtube, about the problem. It is not easy viewing, but very moving.
I was once in a taxi when the driver started texting, he seemed a bit put out when I told him to stop! But at least he did.