Cambodian Prime Minister Hun Sen shows off his inked finger after voting near Phnom Penh on Feb. 25. (Heng Sinith/AP)

FACEBOOK CAME relatively late to Cambodia, only in the past few years, but quickly grew. Surveys show that it is now a leading source of news and information, nearly synonymous with the Internet. This is why a dispute over Facebook in Cambodia bears watching. Democracy is dying in Cambodia at the hands of a despot, and it would be a double tragedy if Facebook helped, however unwittingly.

Cambodia’s long-serving prime minister, Hun Sen, has been relentlessly crushing democratic forces and grinding down civil society. The main opposition party, the Cambodia National Rescue Party, has been dissolved, and Hun Sen warned opposition forces to “prepare your coffin.” The party’s leader was arrested and accused of treason. The regime earlier pursued another opposition leader, Sam Rainsy, with politically motivated accusations; he is now in exile in Paris. Facing an election this summer, Hun Sen has forced the closure of radio and print outlets and ordered the National Democratic Institute, a nongovernmental organization loosely affiliated with the Democratic Party in the United States, to cease operations.

Inexplicably, Hun Sen has 9.5 million “likes” on his Facebook page, nearly twice the number of Facebook users in Cambodia. Sam Rainsy accused the prime minister earlier of harvesting “likes” from click farms and fake accounts, and was sued in Cambodia for defamation. Now, he has filed suit in California federal district court, demanding information about Hun Sen’s transactions with Facebook, insisting the prime minister’s popularity is not authentic. Two years ago, journalists at the Phnom Penh Post reported that only about 20 percent of Hun Sen’s “likes” came from Cambodia, while 80 percent of Sam Rainsy’s were in the country. The prime minister responded that Sam Rainsy is “crazy and stupid.”

Without prejudging the lawsuit’s outcome, the manipulation of Facebook by autocrats raises worrisome questions. Facebook’s founder, Mark Zuckerberg, set out to create an open, neutral platform. But as the past two years have shown , Facebook can be exploited by people with less noble intentions. Trolls, fakers and haters have taken advantage of Facebook in the United States, and no doubt elsewhere. The challenge may be especially acute in Cambodia, where Facebook’s presence is overwhelming. Late last year, Facebook tested a new feature, called “Explore,” in Cambodia and several other countries. The change moved Facebook posts from companies and organizations, including news outlets, to a separate feed, resulting in a significant loss in traffic on Facebook for content from Radio Free Asia’s popular Cambodia service, an independent source of news and information. This probably helped Hun Sen, whether intentional or not. Facebook said March 1 it was ending the “Explore” feature.

Facebook is a mighty force in a small space in Cambodia. The nation’s population is not exposed to the same diversity of news sources as in an open society. Facebook says it is committed to fighting the fake “likes” and the “bad actors.” But what does Facebook do if the bad actor is the leader of a nation? It ought not to neglect this challenge, however vexing.