I can't say that I run into that problem much here in San Diego, though that may be just that we have fewer bicyclists per head. I certainly agree that it would be bad conduct, though. Legally a bicycle is a vehicle and is expected to follow the same rules as an automobile when in traffic—and that includes respecting pedestrian right of way. But my experience with drivers is that most of them are so careful about pedestrian right of way that they won't drive in front of me even if I'm up on the sidewalk and waving them through. I wish your bicyclists were that obsessive.

Of course, it's understandable that law enforcement may take bad cycling less seriously than bad driving, considering the relative kinetic energy. But it's still bad manners.