Ben Kuo's hobby of using satellite images to find out where photos and films were shot helped rescuers find a lost hiker in California's Angeles National Forest.
The hiker, Rene Compean, went out for what he thought would be a two-hour walk in an area he'd hiked in many times but ended up getting lost. He spent the night in the wilderness, completely unprepared. He climbed to a point where he got a faint cell signal and snapped a photo he sent to a friend, asking for help.
The friend brought it to the police and the Los Angeles County Sheriff's Department tweeted it out. Kuo saw it on Twitter and was able to match it with satellite photos of the area to pinpoint the hiker's location so rescuers could find him, The Washington Post first reported.
Kuo explains how he did it to Here & Now's Peter O'Dowd.