My experience? Sure, I've encountered some kooks, held my bag a bit closer in some moments, and maneuvered to the opposite end of the car, just in case said creeper felt the need to give me a Wet Willy or anything comparably as uncomfortable.
For the most part, my biggest issue is germs. I'm hypochondriacal by nature and whenever I have to -yeesshhh- hold onto the handrails, my reflexes call for Purell IMMEDIATELY. But that is the most of my worries.
Regardless, sometimes I listen to this on my iPod, a reminder of a childhood favorite, and I wish my daily modes of transportation were like so: