Isn't it against the law in the United States to use outside channels for government communications? Wasn't this the whole scandal about Clinton? Please correct me if I am wrong.
Amazingly the app is on the governments list of approved apps. The scandal is what they’re discussing on there: highly sensitive information you normally go to very secure channels to talk about.
My understanding is that it was added fairly recently at that, and already this has happened. This must be a record time in "change of policy leading to the most embarassing result". Only a couple of months!
This is a pitfall of having an approved software list (whitelist).
Malfeasance or misfeasance could include flat-out spyware versions of software, often made available in internal "software stores," instead of legitimate software distributed from the developer or through official channels.