Did you know that #Japanese government explicitly endorses Microsoft Windows and Google Chrome for submitting tax documents online?
See: https://www.e-tax.nta.go.jp/download/e-taxSoftDownLoad.htm
The source code of the software for submitting the documents is even not available.
How would it be possible to verify its legality without the source code? The software governments provide must be #FOSS, whose legality and legitimacy can be freely verified.
#Public money, public code.
https://publiccode.eu/ja/