Twitter has owned up to a privacy goof that exposed some Android users’ private tweets. That would be bad enough if the problem existed for an hour, or a day, or a month. But unfortunately for Twitter (and affected users) the problem was present from November 3 2014 until January 14 2019.

https://news.hitb.org/content/twitter-exposed-some-android-users-protected-tweets-and-didnt-notice-over-four-years