President Barack Obama sits with Twitter co-founder and Executive Chairman Jack Dorsey during a "Twitter Town Hall" in the East Room of the White House in Washington, Wednesday, July 6, 2011. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

President Barack Obama sits with Twitter co-founder and Executive Chairman Jack Dorsey during a "Twitter Town Hall" in the East Room of the White House in Washington, Wednesday, July 6, 2011. (AP Photo/Charles Dharapak)