I witnessed a very interesting event on the public transport a couple of days ago.  I was taking the bus on Sunday back to my place in Espoo when the bus driver started an argument with a man of dark complexion since he was having a beer in the bus, which is forbidden.
His answer was quite interesting, as he said "Why can't I do that, if you see plenty of Finns who do?" which regardless of being prohibited actually is the case, especially during weekends or holidays such as Vappu. Even I have done so on a couple of occasions in my student days.
This strengthened my resolve to follow the rules to the T even when some people might not, regardless of whether it is fair or not.  It's the easiest way to stay out of trouble.