I believe that with the increased efficiency in identifying and prosecuting small offenses, punishment should be modulated down accordingly.
Crime happens when the risk of getting caught times the cost of punishment is lower than the benefit of the crime. If you increase the risk of getting caught, you may safely (in fact, you should) decrease the cost of being punished.
How immediate and certain the response to crime appears to be affects the perception of risk.
And even when there's no cop around, other things influence this perception. If there are a lot of people around and things are orderly and many visual cues contribute to the perception of order, the perception of risk is greater.
