As your username says, give me a break. Text messaging while driving is only being attempted to be enforced because it's a measurable act, much like drunk driving or reckless driving. If a cop passes me or glances at me and notices my repeatedly looking down and away from the road, I could be a whole number of things: eating, changing the radio station, trying to flick a bug off me, looking at my GPS, etc. So when I get pulled over, how is he going to accurately check what was happening without relying completely on my word?
He can't. But he can look at your Sent messages and see if you just recently sent a text.
Texting while driving is as dangerous as doing all of the above. They're just singling this out because they (think they) can enforce it. But they can't. Especially when you have phones that do much MORE than just text e.g. GPS or controlling the music playing. So even if I do have a message recently sent within the past two minutes, I could've just been changing the song at the exact moment he saw me, therefore I got a ticket for nothing.
And to just add to this whole rant, don't tell me that it's more dangerous than drunk driving. Drunk driving has many MANY more consequences than texting while driving. Texting is a very temporary impairment, often 10 seconds at most. Drunk driving is the entire duration of controlling the vehicle. That's like saying walking to get the mail gives you more risk of getting skin cancer than laying out by the pool for thirty minutes.