VENEZUELANS LOST access to several social media sites Tuesday after opposition leader Juan Guaidó announced a military uprising against the regime of Nicolás Maduro. The blackout eventually lifted — minutes before Mr. Maduro live-streamed a speech claiming victory over the so-called coup. Then, as Mr. Guaidó prepared to speak Wednesday, crucial services disappeared once again.

The ongoing turmoil in Venezuela has left observers overseas uncertain whether the months-long effort to remove Mr. Maduro had reached a turning point, in any direction. But Venezuelans themselves may know even less about what is happening in their own country. The regime has systematically silenced all independent local outlets, then foreign Spanish-language channels. Now, not even English-language international news can fill the gap: CNN was taken off the air Tuesday just as it aired military vehicles running over protesters. The BBC has also been blocked.

Social media sites have become Venezuelans’ only option amid this censorship, and the role they play in the country is a reminder of all that is ugly and all that is inspiring about the Internet at once. Just as Philippine President Rodrigo Duterte flooded Facebook with misinformation to promote his brutal drug war, the Maduro regime has sought to digitally distort public opinion. (Opposition groups are also hardly innocent of pushing false stories.) There’s a reason Mr. Maduro has not yanked Twitter away from his citizens entirely, and it’s that broadcasting there has been as key to his strategy as it has to Mr. Guaidó’s.

Without Twitter, WhatsApp, YouTube and the rest of them, the problem of viral lies might not exist. But neither would any recourse for Venezuelans who are struggling under an authoritarian president with a stranglehold on information. The opposition relies on social networks to fill the gap, using them to organize and put out calls for protest — laboring especially to reach those in the slums and other areas where Internet access is limited, and where Mr. Maduro may be most concerned that people could turn against him. Everyday citizens use them to stay safe and informed.

Last week, many around the world nodded in approval at Sri Lanka’s temporary platform block after a horrific terrorist attack. This week, they likely watch appalled as Mr. Maduro does the same thing to shut down his critics. Taken together, these stories should teach a lesson: Sites that the world hailed as tools of empowerment are now seen as vehicles for corruption and manipulation instead. What they really are is both.