I'm not sure where you live but what those cars are doing is the correct thing, in regards to laws and driving best practices in what I think are many places in the US. You shouldn't really be going left to get rid of them, even if that's legal where you are (it's not legal to go into the left lane except to pass in multiple states), or you are driving on a highway with three lanes in each direction. The cars should not really be speeding past you on the right either, but if you are weirdly switching lanes they might not have a choice.
Edit: actually, if they are tailgating you too close you might want to try to get rid of them, but tapping your brakes (to flash your rear red lights), or putting your hazard lights on briefly to get them to go around is probably better than going left one lane.
(3 lane, 476 north) What's happening is, they're on auto cruise, they're always a set distance from me (i speed up, they speed up). I go left, they speed up.
I know what they're saying and I've often found it annoying as well.
If such a car is following you and you get to the left or middle lane to overtake a slower car then the car behind you first accelerates to your right as if they were going to pass you, then brakes because of course there's another car there, the one you are overtaking.
The other case where I find them annoying, the worst case for me, is when I'm quietly driving my speed, overtaking a (slow compared to me) car that is following another one. But while I'm overtaking the "auto following" car, the car in front of it gets back to the right lane and the other car suddenly takes off much faster than me. So here I was, driving 110 and overtaking a car driving 90, while suddenly accelerates to 130... until it gets stuck again a kilometer further, and I have to overtake it again, and everything repeats.
Of course, I could do the same acceleration/braking dance and stay behind them all the time, but I care about not spending fuel for useless speed changes.
Edit: actually, if they are tailgating you too close you might want to try to get rid of them, but tapping your brakes (to flash your rear red lights), or putting your hazard lights on briefly to get them to go around is probably better than going left one lane.