This is becoming a theme stretching back multiple administrations. The people at the top either don't understand IT acceptable use policies, cybersecurity controls, classification divisions of systems, records retention policies, etc; or they are intentionally ignoring them. And for bonus points, everyone at this level is an espionage target.
https://en.wikipedia.org/wiki/Bush_White_House_email_controversy
https://en.wikipedia.org/wiki/Hillary_Clinton_email_controversy
https://en.wikipedia.org/wiki/United_States_government_group_chat_leak
This event is already being used for fundraising campaigns.