You can spot the drunks, you have no clue what the idiots who are texting are going to do next
I've learned that texters are usually predictable: they drive 5-10 mph below what everyone else is driving, and they tend to veer to the right.
Doesn't mean all texters are like that, but it gives me a good heads up. When I'm behind one, I usually flash my high beams a few times, as if to say, "wake up, put the damn phone down!"