ISF wrote in an HSNL thread that
"If someone is 3betting polarized (from the blinds) you would be more inclined to 4bet pre (On the button with AA). If they are 3betting linearly you'd be more inclined to flat."
I am assuming this is b/c if someone is 3B'ing a polarized range we do not want them to get there with their garbage postflop. But then I thought it might not be that bad of an idea if they are habitually c-betting their polarized range OOP or if they were spewy, so wouldn't a lot depend on that?

Also if someone is 3B'ing linearly doesn't that mean their range is strong and we should aim to be getting more money into the pot where our 4Bet range is theoretically at our weakest (ie- OTB) even if in fact we are obv at the top of our range with this hand?