Fucking hate people who txt and drive. Only two times that ive almost been in a car accident was because some fucker was txting. I hate it if I'm in a car and the driver is txting. I tell them to knock it off.
Here in Wisconsin they just made texting and driving illegal statewide and in Some cities even talking on the phone is illegal. As others have said, being able to prove it is difficult, but what they can do Is get your phone records and look at what time a message was sent in conjunction to when you got pulled over. Sneaky sneaky.
Just don't txt and drive, it's just not worth it.