Regarding traffic laws for cars, the police themselves drive about ten per cent over the posted speed limit because it has become a cultural norm.
Everyone does it.
Similarly, bicycles practice a number of variations on the law, which work to everyone's advantage.
For example, many bicyclists I know time their arrival at a four way stop so that they can cross with a car.
It remains, though, that since I got my ticket, I have not seen one bicyclist stop at a stop sign for a right turn, if a bike lane exists.
If they want to write me a ticket for doing something non-dangerous that everyone does, then they need to enforce the traffic laws for automobiles at the same level of rigor.
Remember, all of this took place in a bike lane.