Palambok Pusu-Pusu is not an ordinary Facebook group. To join the forum, you must first answer three "tricky" questions in the Toba Batak language, asking to explain your reasons for wanting to join the group with its around 9,600 members. If your answers are off the mark, you might get refused.

"Every day, at least 10 people apply to join the group, but we may not approve a single one of them," said Darman Rajagukguk when we contacted him several w