FOR USE WITH YOUKYUNG LEE STORY SLUGGED SOUTH KOREA DIGITAL ADDICTION DIGITAL, In this Tuesday, Nov. 20, 2012 photo, subway passengers operate their smartphones in Seoul, South Korea. (AP Photo/Ahn Young-joon)
mobile users
FOR USE WITH YOUKYUNG LEE STORY SLUGGED SOUTH KOREA DIGITAL ADDICTION DIGITAL, In this Tuesday, Nov. 20, 2012 photo, subway passengers operate their smartphones in Seoul, South Korea. (AP Photo/Ahn Young-joon)