Immigrants run to jump on a train in Ixtepec, Mexico, during their journey toward the U.S.-Mexico border. President Obama wants nearly $4 billion in emergency funds to deal with the tens of thousands of children from Central America who've been crossing the border. Eduardo Verdugo/AP hide caption

itoggle caption Eduardo Verdugo/AP

Zzarr, a Dutch shepherd, with K-9 handler U.S. Army Sgt. Nathan Arriaga (partly hidden), in 2011. Romeo Gacad/AFP/Getty Images hide caption

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Director of National Intelligence James Clapper (center), accompanied by FBI Director Robert Mueller (left) and CIA Director John Brennan, testifies on Capitol Hill on March 12, 2013. When questioned, Clapper said the NSA did not collect data on Americans. He later acknowledged his response was "clearly erroneous." Susan Walsh/AP hide caption

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Over the last dozen years, whistleblowers at the National Security Agency have had a rough track record, facing FBI raids and lawsuits. NSA/Reuters/Landov hide caption

itoggle caption NSA/Reuters/Landov

President Obama pauses while speaking about the situation in Iraq on Thursday. Obama said the U.S. will send up to 300 military advisers to Iraq and set up joint operation centers. Jacquelyn Martin/AP hide caption

itoggle caption Jacquelyn Martin/AP

Iraqi Shiite tribesmen show their enthusiasm Tuesday for joining Iraqi security forces in the fight against Islamist militants who have taken over several northern Iraqi cities. Haidar Hamdani/AFP/Getty Images hide caption

itoggle caption Haidar Hamdani/AFP/Getty Images

Senate Intelligence Committee Chair Sen. Dianne Feinstein, D-Calif., questioned whether phone companies would retain calling data. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP