The left lane is the passing lane. It varies by state interpretation, but common law is that it is as illegal to impede traffic in that lane that wants to go faster as much as it is to break the speed limit. They're two different traffic violations and you don't get out of yours by enforcing the other. You, yourself, should obey them both and let the highway patrol worry about the other guys. Speaking of, you're not a cop (presumably). If someone wants to be an idiot and go fast, let them go by. No one is paying you to do traffic enforcement and you don't need to be some traffic enforcement vigilante. Odds are, you'll encourage them to take riskier and more desperate moves. You can smugly congratulate yourself when they cause a collision that hurts someone while inconveniencing hundreds or thousands of others. But I guess at least you have the satisfaction of being able to tell yourself, well it was their own fault. Just let the dumb kids go by. They'll probably grow out of it.