FACEBOOK POST: A pro-democracy blogger broke the news of his own detention and eventual release in Vietnam through Facebook, another sign of how the social network is shaking up the country's activist movement and worrying its authoritarian rulers.

FACEBOOK POST: A pro-democracy blogger broke the news of his own detention and eventual release in Vietnam through Facebook, another sign of how the social network is shaking up the country's activist movement and worrying its authoritarian rulers.

OVERSEAS TRIP: Activists who traveled to the airport to greet Nguyen Lan Thang said he was picked up there on his return from a three-month overseas trip where he met with human rights groups and representatives of international organizations, including the United Nations.

DETAINED, RELEASED: In a video message posted by activists soon after his detention at the Hanoi airport Wednesday night, said, "When you see this video, it's certain that I have been arrested by security forces." On Thursday afternoon, Thang said he been released, also via Facebook.