Technology to filter photos in Web searches may help the Justice Department curb online trafficking in child pornography. The department has thus far focused its efforts on prosecution, not prevention. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Devon Energy Corp.'s steam generation plant uses steam-assisted gravity drainage to extract bitumen from oil sands near Conklin, Alberta, on June 28. Jimmy Jeong/Bloomberg via Getty Images hide caption

itoggle caption Jimmy Jeong/Bloomberg via Getty Images

Alvin Toffler, author of Future Shock, sits outside a restaurant on Sunset Blvd in Los Angeles on July 14. Martin Kaste/NPR hide caption

itoggle caption Martin Kaste/NPR

A worker walks along a long pipeline used to convey sand pumped from 20,000 feet offshore to build barriers to keep oil from entering wetlands near Grand Isle, La., last month. Jae C. Hong/AP hide caption

itoggle caption Jae C. Hong/AP

Facebook CEO Mark Zuckerberg has made it clear in recent days that the company plans to change its privacy settings in an attempt to satisfy concerns from users and Congress. Marcio Jose Sanchez/AP hide caption

itoggle caption Marcio Jose Sanchez/AP