"Hello, Twitter! It's Barack. Really! Six years in, they're finally giving me my own account."
With that inaugural Tweet sent from a smart phone in the Oval Office before jumping on Marine One Monday, the President of the United States Barack Obama - or POTUS - cast off security and bureaucratic chains in place since he was elected.

The account - which already had nearly 150,000 followers in the first half hour - will instantly become one of the world's top hacking targets, but it will also allow Obama to communicate directly for the first time.

Until now Obama has tweeted through his executive staff WhiteHouse or the remnants of his campaign staff BarackObama.

"The POTUS Twitter account will serve as a new way for President Obama to engage directly with the American people, with tweets coming exclusively from him," the White House said.

The already verified account features the customary headshot of Obama, but also a background photo of him walking over the Edmund Pettus Bridge in Selma, Alabama, in March, when he marked the 50th anniversary of a civil rights march that changed America.

Obama describes himself as "Dad, husband, and 44th President of the United States."

He is following an assortment of cabinet members and senior staff, as well as wife Michelle Obama.