[Turbo Pig]

If _their_ mask works, how can they be affected by someone without one?

Because they are pushing wearing a mask as a way for you to protect others, because you MIGHT be sick. Billboards in the KC area literally say, "I wear mine to protect you. You wear yours to protect me".

[ROCKLOBSTER]

because you MIGHT be sick.

And I might not....Go ahead punk, take my temp.

If you're asymptomatic, you can't spread the virus.