All of the devices along with the server belong to the government. None of the e-mails or other communications are private. All are public property and can be viewed by anyone including all of us. Although you might have to file a lawsuit through the freedom of information act to get it and some sensitive material could be deleted. Anyone working in a government job knows, or should know this.
There may be some illegal activity in the investigation, but this isn't it.
Wrong, read the OP and the attached Federal Statutes.
