I don't advocate doing it every time, but if all the lanes are open and the dipsh*t wants to ride my tail when there IS a clear passing I am under no obligation to encourage his behavior. I once put a guy in the ditch while going to the midnight movies, three cars on the road, My buddy and his girl in his car, me and my girl in mine, and this dip in a van, he got on my tail so close I couldn't see his headlights in my rearview, and wouldn't move even though the pass lane was clear, I did everything short of pulling over to 'be nice' and let him pass, changed lanes, slowed down, sped up etc, and he still rode my tail, so I just told my girlfriend to braced herself, braced myself and locked up the brakes, he went into the ditch after tapping me, no one got hurt, so I don't feel repentant in any way about it.
If it's bumper to bumper traffic I say live with it and worry about the cars in front of you, but if it's an open road and there is no reason whatsoever that the driver can't pass (passing lane, broken yellow, no traffic etc) then do what you need to do, at the risk of sounding paranoid, and attributed to living an big cities, if there is absolutely no reason for someone to be acting the way they are, (riding my bumper on an open road is a good example) I tend to start asking myself WHY?
Also, when driving the truck I get passed a LOT, simply because if I drive 70-80, I get 18-19mpg, if I drop to 65, I get 24-25mpg, and it generally only takes a few more minutes to get where I'm going so I'm happy to cruise along at 65. and stay in the slow lane except when passing someone even slower.
Also few states have laws that say you have to pull over to allow faster traffic by, but EVERY state has laws against tailgating
Ken.