BEIJING — When the cyclone hit her homeland a week ago, Mya Moeswe was frantic about her sister back in Burma. Thousands of miles away in Vancouver, British Columbia, the 38-year-old mechanical engineer sobbed as she tried over and over to get through on the downed telephone lines.

Desperate for information, she turned to the television networks and the mainstream press, only to find them overly broad, general, too out there. The one thing that spoke to her as she faced the void: the network of expatriate Burmese Web sites stocked with invaluable, up-close details that helped her make sense of the devastation before her sister finally called out with the news that they’d lost a roof but were otherwise OK.

Part newsstand, town hall, bulletin board, and cheerleader, these virtual communities have played a vital role in easing heartaches in the last week, managing to evade the long arm of the cyber police, and thwart an isolated, repressive regime to bring news and personal information to the world.

Burma has one of the world’s most censored press communities, according to Committee to Protect Journalists, a watchdog group, with a tightly controlled official press and Internet filtering that blocks Google and Yahoo e-mail, the BBC, and the diaspora Web sites.

In this environment, news gathering for the expatriate Web sites is done by informal networks of anywhere from a handful to several hundred volunteers inside Burma sending stories, tidbits, video clips, and still shots out through Internet cafes, public phones, or with departing travelers.

Some are given equipment and a few hours in reporting basics; others find their own way. While the journalistic standards vary widely, some participants even call police stations and government officials for comments or a response.