I have no idea why that is a thing and certainly not why so many public figure
leave it on.
A Venmo account under the name “Michael Waltz,” carrying a profile photo of the national security adviser and connected to accounts bearing the names of people closely associated with him, was left open to the public until Wednesday afternoon. A WIRED analysis shows that the account revealed the names of hundreds of Waltz’s personal and professional associates, including journalists, military officers, lobbyists, and others—information a foreign intelligence service or other actors could exploit for any number of ends, experts say.
...TAP printed the full
list.
