First, as Buzzfeed reported, Obama’s first tweet from this account was sent using an iPhone registered to the Executive Office of the President — the government name for the sprawling presidential staff — which is not a device Obama regularly uses.
The president used the iPhone to post the tweet for security reasons, telling TV host Jimmy Kimmel in March that his own phone, a modified Blackberry, doesn’t have functions like video or audio recorders, leading some to speculate that his Blackberry isn’t cleared for Twitter use either.
The president also has posted to Twitter in months past on other accounts, such as one in his name — @BarackObama — and @WhiteHouse. Each is run by various staff members, and when Obama personally tweets from either, he signs with “-bo."
The new Twitter handle @POTUS will serve as the official presidential handle in coming years, first for Obama, and for future presidents too.