People are required to wear masks in high schools and on public transportation – or risk being fined. Shopkeepers also have the right to ask customers to wear masks or to please leave. Artificial-intelligence-integrated video cameras will be monitoring overall compliance on the Paris Metro.
Last I looked, last week, there is still no published scientific research showing the use of home made and improvised (bandanna) face masks has any impact on reducing the spread of SARS-CoV-2. Cloth face masks were used in 1918-1919 and subsequent research found they had no effect, and preliminary research on SARS-CoV-2 and cloth masks (published April 6, 2020) found cloth masks were ineffective in stopping the spread of SARS-CoV-2. Would be nice to have solid evidence that these measures really do stop the spread of the virus.
There is evidence that certified, manufactured surgical face masks (made from blown polypropylene, not woven cotton) and certified N95 (and similar masks) do offer protection. The problem is there is no evidence that home made masks, made of random, unapproved designs, using uncertified materials, and assembled by strangers of unknown skills provides any protection. If you do not understand the problem, please research the issue.
The solution is for the CDC to recommend specific designs, materials and construction methods and/or for the wide availability of certified face masks.