Cops on the road

My morning commute is approximately 32 miles. (Oddly, my evening commute is exactly the same.) The first part of the trip in the morning involves driving down Highway 71, a recently-refinished curvy 4-lane highway with light traffic. That part of the drive is typically uneventful.

Yesterday, I took the usual entrance ramp onto the highway. At the next exit, a Sheriff's car entered the highway. I settled into the right lane with my cruise control set to the speed limit. The Sheriff moved to the right lane and set his speed to match mine, plus approximately 0.0000000004 mph. Over the course of 15 miles, he slowly crept up on me, until he was right in my blind spot. Here we are on a big, wide-open highway, very little traffic other than us, and
he chooses to park his car 3 feet from my left rear fender. I slowed down slightly to give him a chance to pass, and he did. As he went past, I noticed that he was busy using the "cop laptop" mounted on his dashboard for something. He was splitting his attention between his driving task and some kind of important thing he was doing on his computer.

I'm not sure, but I think that kind of thing is illegal for everyone else. I'm pretty sure I would get a ticket for driving like a dipstick and using a computer when I was supposed to be watching the road. I wonder if it's illegal for cops. I also wonder what he was doing on that computer. He wasn't laughing, so he probably wasn't watching videos on YouTube or something. My guess: He was using Twitter, letting all of his "buds" and fellow cops know what he was doing moment to moment.