U.S. Secret Service agents stand guard during a visit by U.S. President Barack Obama to the Demond Tutu HIV Foundation Youth Center on Sunday, June 30, 2013, in Cape Town, South Africa.

 

              U.S. Secret Service agents stand guard during a visit by U.S. President Barack Obama to the Demond Tutu HIV Foundation Youth Center on Sunday, June 30, 2013, in Cape Town, South Africa.
U.S. Secret Service agents stand guard during a visit by U.S. President Barack Obama to the Demond Tutu HIV Foundation Youth Center on Sunday, June 30, 2013, in Cape Town, South Africa. (AP Photo/Evan Vucci)