Rumour on the street is that the advice is in place because local governments don't want people hoarding face masks, because there's a massive shortage of it in most Western countries, [1] so much so that several hospitals have eveb asked for private donations of face masks, and even the Directorate of Health. [2] This is half admitted at least by my own health authorities in Norway.

The advice from the Norwegian "CDC", the NIPH/FHI, was that you shouldn't wear a mask! [3] The claim, as it was broadcast in an interview, was that there is no evidence that wearing a mask protects you from contagion. This again springs out of the advice from the WHO. But they also claimed that it's in fact a danger of spreading the disease by wearing a mask! [4] [5] Except it's pretty controversial, and there are studies that directly contradict the official advice, for instance the now infamous bus study from Wuhan (now retracted),[6] but there are others. FHI has since relaxed this verdict, and there are news stories of them even turning 180 and advicing the use of face masks.[7]

[1] Norwegian language source: https://www.varden.no/nyheter/mangel-pa-munnbind-sykehusene-... [2] Norwegian language source: https://www.dagsavisen.no/nyheter/innenriks/helsedirektorate... [3] Norwegian language source: https://www.fhi.no/nettpub/coronavirus/fakta/renhold-og-hygi... [4] Norwegian language source: https://www.nrk.no/osloogviken/munnbind-kan-fore-til-mer-smi... [5] Norwegian language source: https://forskning.no/ntb-sykdommer-virus/fhi-munnbind-gir-fa... [6] https://www.dailymail.co.uk/news/article-8094933/How-one-man... [7] Norwegian language source: https://www.vg.no/nyheter/utenriks/i/GGLm0l/helsedirektorate...