Vietnam has launched a crackdown on dissident blogs, ordering police to arrest the owners of three sites that have been harshly critical of the communist regime—a sign that the government plans to tighten its information stranglehold on the country’s rapidly growing Internet use.

One of the blogs, Danlambao, or “The People’s Journalism Blog,” has grown particularly popular recently through its speculation on power struggles at the very top of Vietnam’s leadership related to the arrest of a banking tycoon in August. On Wednesday, Prime Minister Nguyen Tan Dung denounced Danlambao and two other blogs as “villainous plots by hostile forces,” declaring that they had “publishing distorted and fabricated articles” and calling for “serious punishment” against their owners, according to Voice of America.

Two of the three blogs have vowed to continue. In a defiant post Thursday, Danlambao’s operators promised that they were “prepared to be repressed and imprisoned rather than leading the life of a dumb dog that dares not to bark.” They later boasted to the Associated Press that the site’s traffic had nearly doubled to 500,000 pageviews in a single day, thanks to the national media attention it had received.

Vietnam boasts a highly wired population—30 percent of its 90 million people have a connection to the Internet—and blogs have become an increasingly common tool of self-expression and amateur muckraking. The government has frequently resorted to blocking the sites and arresting their owners. At least five journalists and 19 bloggers are currently being held for a variety of charges in Vietnam, according to Reporters Without Borders.

Photo by Hector Garcia