Two of my biggest pet peeve's are people driving slow in the passing lane and tailgaters who just seem to love to drive as close as they can ... even when there is a huge line of cars and nothing anyone can do about it.
Both of these type drives ... well maybe if they do one they also do the other .... are dangerous.
I have considered a pop up sign for the 2nd type that says the "closer you follow the slower I go."
I don't know any solution for the passing lane driver ..... maybe we could be empowered to ticket another driver if we had video proof of their bad driving.