In that case people who wear a mask and then wear their mask under their nose then breathe out of their nose, causing small snot droplets to land on the outside of their mask and walk around like this. Then they touch their snotty mask and then proceed to touch things. It is disgusting. Just get rid of the mask.
Agreed the masks are bad and never should have been introduced. (But people can at least get oxygen with their noses not covered.)