The use of mask has been so prevalent, its mechanism so very simple and intuitive, its down-side so little, that I think in this case, the burden of proof is on

The use of mask has been so prevalent, its mechanism so very simple and intuitive, its down-side so little, that I think in this case, the burden of proof is on the other side. Unless scientists find evidence that proves the masks to be useless or harmful, I'll continue to wear mask when I absolutely need to go out.