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Authy got hacked, and 33 million user phone numbers were stolen
(appleinsider.com)
This is a most excellent place for technology news and articles.
GA now backups your codes in your Google account, so this doesn't happen anymore.
They had an obvious solution which is export to an encrypted text files and went with the option that lowers your security
Google usually goes with the lowest common denominator solution. There is a staggering amount of people who don't know what is a file, let alone that phones have any.