While I wouldn't do it personally, I can understand people's frustration and anger.
Where else are they going to direct it? This is a time when it'll get national attention.
People are starving right now. People can't afford to heat their homes right now. People are staring at the possibility of redundancy because their employer can't afford to keep them on/the business open right now.
This is all happening right now. For people who are suffering right now, there is no other time or place than right now.
While you nor I would act in this manner ourselves, please don't criticise those in society who feel they have no other option left to draw attention to their plight.