We already know and have mountains of proof it works now (and from 1918 when they were used to prevent the spread of the Spanish Flu). It's not up for debate, its scientifically proven they reduce the spread of COVID-19. There's no medical condition besides maybe a physical deformity or someone with a severe mental disability where they'd rip it off their faces preventing someone from following the law. People who have gotten lung transplants, have heart conditions, asthma etc can do it without making a scene about it. The people complaining they can't to make a statement (while potentially endangering others) can order things online, use curbside pickup or find alternative means to shop that don't affect other shoppers.
Hopefully the police finds out who is doing this and arrest them. Didn't mean to derail this thread but I'm just tired of this coming up.