Suppose you were scheduled for surgery.

Your surgeon walks in to greet you. His face is covered in sweat. He is coughing and sneezing. Apparently he has a rare virus that is highly transmissible.

But he's still able to do the surgery, he just needs to take some meds to give him a boost. And he'll wear a mask throughout the process to ensure you don't get the virus he has. So it's safe.

Or suppose you go to the hot dog stand to buy a hot dog. The guy is clearly sick, sweat pouring from his forehead, coughing and hacking with a box of tissues next to him. It's ok though, he'll put on a mask and gloves before he serves you your hot dog. It'll be perfectly safe.

AT BEST, masks may block little bits of spit. AT BEST.

Everyone knows they cannot stop viruses. You would need a LOT MORE than a mask to stop someone from spreading a virus. 6 feet isn't enough. Staying home and quarantining yourself is really the only way to limit the spread.

But we have a mask, so it's ok, it's not contagious anymore!