1) Here is my personal take on masks (and there are much more knowledgeable experts on this, who might disagree - follow up with @bencowling88 and @Don_Milton). Mask as part of the strategy to mitigate COVID19. They are PART, they are not a magic bullet.....
2).....However, they are efficient to stop spread to a certain extend. We currently don't have enough, therefore the message was, we should limit them to healthcare workers. However, they can be used strategically. People who interact a lot with other people....
3)....like supermarket personnel, hospital receptionists, security staff, police offers etc. should absolutely wear them. These people have a high likelihood to get the virus and transmit it to many others. If you already have them, it is good to wear them in places.....
4)....where you interact with other people inside: supermarkets, the pharmacy, hospitals/ERs, the subway. You don't need them outside (as @Don_Milton will certainly tell you). And don't be hostile towards people who wear masks. These people protect YOU!......
5...Finally, masks help, but they are not a guarantee you won't get infected. They are similar to a car seat-belt. Seat-belts will help to protect you in many car crashes and have saved many lives. But they are no absolute guarantee that you are not getting injured......
6) Again, this is a personal opinion. Look for papers from @bencowling88 and others for scientific data.
