Mr. Boehm, 22, a senior at Stanford University, had gone to Japan in June with the Stanford Chamber Chorale. When the rest of the singers headed home, he continued to travel, carrying his U.S. and German passports.

Like most of his peers at elite universities, he was well plugged in to the world around him, posting regular updates every two to three days on his travels through Southeast Asia. By Aug. 13, he had announced through his Google Plus page that he was in Malaysia.

Then nothing for a week.

Worried, his parents, Bruce Boehm and Nancy Luberoff, got in touch with U.S. and German consular officials in Malaysia and sent e-mails to 12 of his friends. The message went viral. On Facebook, more than 5,000 people subscribed to one of two pages dedicated to the hunt. On Twitter, #JacobBoehm became a trending topic in the San Francisco Bay Area, the home of Stanford.

The first Facebook page was created shortly before 11 a.m. Friday, San Francisco time, by Julian Kusnadi, a fellow member of the chorale. People immediately started joining in, offering suggestions, encouragement and prayers. One suggested reaching out to current and former Stanford students who lived in Malaysia or hailed from there.

Another posted a close-up photo showing just Mr. Boehm’s face. Misha Nasrollahzadeh, doing a summer internship at Facebook, contacted its “safety team,” which offered to run free advertising promoting the page within Malaysia. And that was just in the first 10 minutes.

At that point, a second page, which became the main source of information, appeared. A missing person’s flyer was posted in English, then translated by someone else into Malay. Celeste Brash, who writes the Lonely Planet guide for the area, noted that the village where he had last been seen, Jerantut, is a gateway to Taman Negara, a jungle area that is a vast national park. “Is it possible he went on a long jungle trek?” she wrote, offering local contact information.

Mr. Boehm’s father suggested that it was unlikely that he would make an unannounced multiday trip into the jungle, as it was “not his sort of thing.” More suggestions and offers of help came forth, including one from Timothy Tam, a Stanford student whose father works in the office of Prime Minister Najib Razak of Malaysia.

The hours passed as the search went into high gear in Malaysia, focusing on the national park. Finally, at 10 p.m., Friday, San Francisco time, came a piece of news, from the U.S. Embassy: “The park rangers informed us your son checked into the Tembeling River View chalet in the town of Kuala Tahan (approximately 1 hour driving north of Jerantut) on August 15th and checked out on the 17th. He did not obtain a permit to enter Taman Negara national forest. The rangers will continue searching. We will continue checking with them and other contacts.”

The circle widened via Twitter and Reddit. Several Malaysians who had joined the effort on Facebook noted that anyone entering Taman Negara is required to have a permit and a guide and that people without guides can occasionally get lost. And there is generally no cellphone or Internet access.

At about 8 a.m. San Francisco time Saturday, 21 hours after the first posting on Facebook. Mr. Boehm had been found in the park and was in communication with U.S. officials via two-way radio. Asked what had happened, he reportedly said, “It’s a long story.”

Ms. Luberoff said in a statement that the “real story” was not her son’s disappearance, but rather that “thousands of people worked together to find him.”

“We are so grateful for this spontaneous community and outpouring of support,” she said. “I hope it becomes a model for others.”

Source: nytimes.com