I agree with all above about the inappropriate touching and your right to be annoyed/angry about it. However, the last post about the high-wheeler made me realize something- it's all about the comedic, "fun" aspect of the ride. Folks probably can't imagine that you'd take issue with them messing with your "clown car" bicycle. It's all a big joke- right? So what's the big deal?
Most people already consider bicycles a toy, but when you pile-on with penny-farthing wheelsets, or triplet frames, then you're just taking it to Steve Martin levels of absurdity- so why not get in on the joke?
The reason I bring up Steve Martin is because his use of the banjo in his early comedy routines engendered a similar reaction. He was, and is, a serious and skilled practitioner of the 5-string banjo, but he recognized that in the public square the banjo had a ridiculous quality. So he used that assumption, and his skill with the instrument, to augment his comedy in a really effective way. But most folks still considered his banjo-playing nothing more than a sight-gag. (Which in his case was fairly intentional.)
But getting back to the bike. To most people the idea of using a bicycle as a serious form of transport, and one to be considered the equal to an automobile, is simply incomprehensible. So when a bicycle such as the triplet or the high-wheeler comes into view, it's clown-car time and all fun and games. Who would think to deprive them of the amusement?

I'm beginning to find myself drifting into a rant, so I'll stop here...
cheers, Joe

oh yeah, 5-string rules!