When a couple students clacked away on their keyboards during a lecture earlier this week, I crossed to the dark side. “There’s no need to check the Net right now, so if anyone here is, I’d appreciate it if you stopped,” I told them.

But when the clacking resumed a couple minutes later, I kinda lost it. “If you must check the Net, please step outside,” I said, working to keep my voice level and avoiding calling them out by name. “It’s distracting to everyone else.”

They stopped. But the sullen expression on one of their faces seemed anything but contrite. If anything, it said, “how dare you.”

For other classroom veterans, this may be old hat. These kids are undergrads, after all. Some don’t want to be in the class, don’t even want to be in school. And odds are pretty good that they’ve gotten away with sullen looks and rudeness before, at home or in class.

To me, however, it’s all new. When I’ve managed adults, I’ve had to be blunt to set people straight. “Just do the fucking work,” I told one staffer through clenched teeth during a frustrating evaluation session. (Hardly the kind of encouragement HR folks would like. But he later did go on to be a prize-winning investigative reporter.)

Of course, I can’t say precisely that to the kids. Nor do I want to. Instead, I want them to be as excited about journalism as I am. I want them to get the message that what we do and how we do it matters. Pulling the verbal equivalent of a Sister Attila knuckle-rapping session doesn’t seem like a way to get them revved up.

In fairness, the dozen other students were paying attention. Some might even have been getting as jazzed about the topic as I was. When many spoke up at points, I knew I was getting through. (These Nebraskans can be far too reticent.)

And the work that many of these kids do is outstanding — some of it ready to run in just about any newspaper in the country. In another class this week, one on magazine-writing, the work was good, so evocative, and the emotion so potent that it moved me close to tears. No exaggeration. Really heavy subject.

It’s the problem kids, however, that I find hard to shake off. The same sullen-looking Net-checking student, in a later class, turned in work that missed the mark in too many spots. Drove me bats. But it was the student’s reaction — annoyance at my questions, instead of embarrassment at a lack of answers — that really stuck in my craw.

Other teachers tell me it’s a generational thing. Some of these kids have been told how great they are all their lives, one colleague told me, so who are we to question them? If we do that, it’s we who must have a problem, not they. Certainly there can be nothing wrong with their behavior. And checking the Net in class is everyone’s right, isn’t it?

My son tells of how one of his profs at Boston University blew his cool during one talk. A student was reading the newspaper as the fellow was lecturing. The prof walked up to him, told him to leave the class and never come back. He wasn’t welcome in the room. Kid never returned.

Bravo! Before this week, I might have thought the prof was coming down a bit too hard. I might have even believed the problem was that he was a bore who couldn’t keep the kid engaged. Now, I’m with the prof. And I wonder if I should have tossed the students out this week. I hope the day doesn’t come when I’ll have to, but I’ll be ready, ruler in hand.

Bit sad, you know.