Richard M. Nixon, then seeking the Republican presidential nomination, addresses an audience in Oregon in May 1968. AP hide caption

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Photographers take pictures of a display of current and former Bell council members who were arrested on corruption charges during a news conference Tuesday in Los Angeles. Kevork Djansezian/Getty Images hide caption

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Facebook founder and CEO Mark Zuckerberg speaks during a news conference in August at company headquarters in Palo Alto, Calif. Justin Sullivan/Getty Images hide caption

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In this Aug. 7 photo, a Mexican journalist protests the targeting of journalists by drug cartels and others in the country. The unrest has prompted some journalists to seek asylum in the U.S. Marco Ugarte/AP hide caption

itoggle caption Marco Ugarte/AP