The Vote Joe app, used by the Biden 2020 Presidential campaign, was found to be leaking potentially sensitive information about voters, such as their political affiliations and past voting choices. The app also didn’t enforce email verification which would let anybody, including non-US citizens, download the app and have access to this data. Users could create fake phonebook contacts to “pollute”” the data being harvested by the app’s creators. The team promptly patched these security flaws in the iOS versions of the app by September 11th.”
Source: https://www.bleepingcomputer.com/news/security/us-2020-presidential-apps-riddled-with-tracking-and-security-flaws/