In most US municipalities there are rules for riding bicycles. Here in MN the law clearly states bicyclists have a right to the road, and can ride on the road, staying "as far right, as safe vehicle handling will allow."
Not many drivers read the vehicle/road codes and laws. They are only interested in getting the little plastic card that, they think, gives the right to rule the road.
As far as stupid things said to me while cycling, and there have been a few, this one came from a motorcycle cop sitting at the side of the road with his radar gun. He'd clocked me and as I rode by, coming from a dead stop at a light(something I don't always do, except when there're cops around) he announced his reading to me 12 miles. Boy what a stupid thing to say.
The last one came a couple weeks ago, for the life of me I have no clue what it was about, just a few teenage (I assume teenage) boys out for a cruise, pass me and yell out "Nice a55!" It had me thinking of a snappy come back for the rest of the ride, and then had me thinking about what would provoke someone to say that. I even checked to make sure my shorts weren't see through(God forbid, I'd be showing my a55 off to the world).