dbakl, the vintage Harley collector crowd is the worst on the planet. They even think old HDs are not supposed to drip oil.
If you want to have some fun, hide a small oil can in your pocket, squirt a few drops on the ground under their bikes, watch them freak out.
I had a weird encounter with a guy, he asked me, How much for my Alex Singer, I said make me an offer, that went nowhere "no offer", He then said you shouldnt be riding it, I said, Well, looks like you wont be riding it.