Corn farmer Jerry McCulley sprays the weedkiller glyphosate across his cornfield in Auburn, Ill., in 2010. An increasing number of weeds have now evolved resistance to the chemical. Seth Perlman/AP hide caption

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A school official shows a pupil an infrared digital laser thermometer before taking his temperature in Lagos, Nigeria, in September. Starting this week, similar hand-held devices are checking foreheads for fever at some U.S. airports. Akintunde Akinleye/Reuters/Landov hide caption

itoggle caption Akintunde Akinleye/Reuters/Landov

"The sexts are currency," explains Hanna Rosin. Teenage girls told Rosin boys collect the photos like "baseball cards or Pokemon cards." iStockphoto hide caption

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Microsoft says it's patching a Windows security flaw cited in a report on alleged spying by Russian hackers. Ted S. Warren/AP hide caption

itoggle caption Ted S. Warren/AP

John Yoo, a former lawyer with the U.S. Department of Justice, argues that the NSA's phone records surveillance program is constitutional. Jeff Fusco /Intelligence Squared U.S. hide caption

itoggle caption Jeff Fusco /Intelligence Squared U.S.

By this time next year, U.S consumer are likely to be using credit cards with electronic chips, like these in Germany. But such cards are expected to stop only 60 percent of fraud, prompting a retailers' spokesman to call them the "not-so-smart card." Martin Meissner/AP hide caption

itoggle caption Martin Meissner/AP

Kmart says it has removed malware that had infected its checkout registers in stores. The company believes the malware may have been in place for about a month before it was detected. Rachel Murray/Getty Images hide caption

itoggle caption Rachel Murray/Getty Images