"More minor violations include using expired tickets, smoking on a train or not walking a dog on a leash."

Now imagine the power of cops in such a state. They can destroy your life with little effort, espacially since restrictions of your life will probably snowball into more offences. E.G: how do you pay your taxe if you can't move to get a job ?

I don't doubt corruption is part of the program, but nobody is going to take down a cop at the risk of having 10 of his friends following every one of your step for the next month.