Just had an incident this morning when I was riding to work. Passed by a house in my neighborhood, heard barking, looked back and a little puppy started to follow me. Off leash, of course. I know this puppy. She has run across the street at me before when I was getting my mail.
No harm -- the puppy was frightened by my bicycle, but as soon as I stopped, put my hand down and pet her, she was overjoyed to get some love. Her owner scooped her up and thanked me.
BUT COME ON, PEOPLE. Your dog doesn't have to be a little hellion to keep her on a leash. At the very least, think about that dog getting run over by a car because you decided it was okay to work in your front yard while your tiny puppy plays, unrestricted. If I hadn't stopped, that puppy would have continued to follow me. Lots of dogs are afraid of bicycles, especially if they're not used to them. They think the bike is an intruder that they must run off. Because I stopped, I probably saved this puppy from thinking that bicycles are bad (and perhaps prevented the puppy from attacking a bicyclist when she got older), but that won't help when the puppy decides to chase a car, or a runner, or whatever else fancies her attention, and then gets lost or run over.
For the record, one of my little dogs is what most of ya'll would think is a little hellion. She's got issues (the product of two "puppy farm" dogs, she has both psychological and physical defects). I socialized her like crazy when she was a puppy, but she still developed fears of children, bicyclists, runners, strangers (not cars though--go figure). I have adopted a manage strategy with her. I simply don't put her in situations where she would be exposed to her fears. It's difficult to train those fears out of a dog, especially when you're by yourself. Most of the techniques used to alleviate fears involve the use of at least 2 people (one to control the object of the fear, the other to control the dog). So far I don't have that kind of support I can rely on, so I manage by not putting her into situations where she could get into trouble.