I'd like to think they'll shrug their shoulders and think 'idiots' before going about their normal day (if they even see it).
Arresting people for mocking deaths, whether its about cancer, kids, helicopter crashes, tragedies or whatever is pointless and a waste of time. As someone above said, valuable resources gets put into this, for nothing but a crime statistic to help boost the numbers.
I genuinely see grown blokes getting angry about these chants inside the ground and wonder how they get through life in the real world.