White House Switching To Private Email

Think Progress is keeping a running total of various » White House switching to private email stories. It seems since the Purgegate investigation into white house emails, many staffers have given up using the White House mail system "except for purely professional correspondence" and are using RNC email systems or their own private email. Then Josh Marshall points out that while this might avoid being seen in the White House email system, if subpoenaed there can be no claim of executive privilege to protect these messasges. And someone else points out that other agencies "have apparently banned this practice over security concerns". I guess it depends what you mean by security.