And the people who behave inappropriately in public places take great comfort in the fact that people around them are too afraid or apathetic to approach them.
Sadly, many public employees do not take the necessary action to stamp out these rule breakers as well. That's why I appaud the library staff's action.
There have been a few times where I had to tell the mrt staff that people were eating and drinking in the trains and the stations. I have told them off personally a few times we well. I'm prepared to get confrontation if necessary, getting really sick of spoilt brats in this world (both adults and children).
I know what you mean when you say that the general public is apathetic when they see what is happening in front of them. They do not realise that in keeping quiet they are also as guilty as those who misbehave.
Good people like you know that it does not need rules and enforcement to know the difference between right and wrong. What we observe is a lack of civility and care for others which brings us to decide upon ourselves to try to stamp it out.
Do feel encouraged and be brave because what you are doing is right and it is a shame for those who feel otherwise. I myself have confronted a few of these passengers in the MRT before. They will comply if you are stern with them. Stern but not rude.
Best of luck but the rewards are satisfying.