A force is emerging at last to check the world-bending power of Big Tech. It isn’t Congress, whose hearings so far have amounted to little more than political theater. It isn’t U.S. regulators, whose occasional wrist slaps have largely been ineffective deterrents of corporate overreach. And it isn’t consumers, who have continued to rely heavily on internet giants’ products even as scandals have shaken their image.

No, the calls to action that are starting to make a difference are the ones coming from inside the house. It’s tech workers—from highly paid software engineers to poorly treated contract workers—whose voices are resonating in Silicon Valley and Seattle now.

At Google this month, an employee walkout successfully pressured the company to change how it handles sexual harassment accusations—and other tech firms quickly followed its lead. Google employees previously got the company to drop a contract with the Pentagon that involved military applications of artificial intelligence. Now they’re calling publicly for the company to cancel a project to build a censored search engine for use in China.

Amazon warehouse workers in Europe spent Black Friday weekend protesting their working conditions. That’s after Somali warehouse workers in Minneapolis organized last week to force Amazon executives to negotiate with them. In October, an anonymous Amazon employee spoke out against the company’s work with police departments on face recognition. Employees have been protesting that project internally for months. Microsoft workers have also pushed back against their company’s work with Immigrations and Customs Enforcement.

But there is one tech behemoth whose workers have stayed oddly quiet, even as it has been pilloried by outsiders for everything from its privacy practices to its effect on democratic elections to its role in ethnic violence around the world. Employees of Facebook, possibly Silicon Valley’s most controversial company, held their peace even after a New York Times investigation that showed a pattern of company leaders conniving, dissembling, and kowtowing to conservatives as the platform’s problems mounted.

It’s time for Facebook’s workers to speak out. Past time, really. But now would be better than never.

Since President Donald Trump’s election, in which Facebook played a supporting role, there have been occasional rumblings of employee discontent. Facebook, to its credit, has an internal culture that encourages employees to speak up within the company or within their team—an approach that likely helps to defuse some anger that might otherwise explode beyond its walls. But Google has that too.

What Facebook also has—more than Google, at this point in its maturation—is a culture of solidarity, a sort of us-vs.-the-world mentality in which wagons tend to circle publicly even when they’re privately at loggerheads.

It’s a company whose CEO used to close all-hands meetings by raising his fist and saying, “Domination!” A company where a top executive wrote an internal memo making the case for prioritizing growth at all costs—even at the cost of human lives. A company whose staff broke out in cheers at a meeting when CEO Mark Zuckerberg announced that he had tracked down and fired an employee who leaked word of a secret A.I. product to the press. As one anonymous Facebook employee explained to Recode’s Mark Wagner afterward: “You don’t betray the family.”

That cultlike loyalty helps explain why, when Facebook was under fire earlier this year for having allowed shady app developers to harvest users’ profile information, the word out of Menlo Park was that Facebook employees were rallying around their chief. There were rumors of employee anger after Facebook’s top policy executive, Joel Kaplan, turned up to support Supreme Court nominee Brett Kavanaugh at the Senate hearing in which he was accused of sexual harassment. But even then, no one dared speak up publicly.

The silence held even after the Times reported that Kaplan, along with COO Sheryl Sandberg, had systematically downplayed evidence of Russian interference and misinformation to avoid upsetting conservatives on Capitol Hill. Bloomberg reported this week that some within the company are now questioning Sandberg’s leadership. No doubt Facebook’s largely liberal employees are struggling to reconcile their previously held vision of Facebook as an idealistic, mission-driven enterprise with their bosses’ Machiavellian machinations. But again, they’re doing it anonymously and vaguely, via back channels—perhaps partly as a way of shifting blame from Zuckerberg himself. There are no plans for walkouts at 1 Hacker Way.

What murmuring there is seems to be having little effect: Zuckerberg is both standing his own ground and standing by his right hand, saying he hopes to keep working with Sandberg for “decades.” The company even managed to get its outgoing communications chief to take the fall for the most explosive claim in the Times story—that Facebook had paid a D.C. political consultancy to spread an anti-Semitic smear against a civil rights group that was criticizing it. “Responsibility for these decisions rests with leadership of the Communications team,” Elliot Schrage wrote in an official Facebook blog post last week. “That’s me. Mark and Sheryl relied on me to manage this without controversy.”

It’s clear by now that Facebook’s leaders respond to outside criticism defensively—and sometimes even offensively. The company’s board seems content as long as the profits keep flowing. Users have tried quitting Facebook—only to end up spending more time on WhatsApp or Instagram, both Facebook products. Congress can’t agree on anything, and regulators under Trump are content to do nothing. Right now, realistically, change can only come from within. But in Facebook’s case, so far, it isn’t coming.

On one level, it’s understandable that Facebook employees have kept quiet about their company’s malfeasance. Some of them probably genuinely feel that the company has been unfairly attacked. Others would like to speak up, but they’re scared. An anonymous former employee told the Guardian that despite its warm and fuzzy image, Facebook enforces secrecy by sowing fear: “If anyone steps out of line, they’ll squash you like a bug.”

But it’s increasingly clear that tech companies’ own employees are the only ones in a position to effect serious ethical reform right now. And the tactics that have succeeded elsewhere do not include quietly raising concerns up the chain of command or privately sharing doubts in internal meetings. What has worked is whistleblowing. What has worked are walkouts. What have worked are specific, public demands.

That’s what the world needs from Facebook’s employees. We need them to speak up about data collection, about face recognition, about political cowardice, about racial and gender bias, about the platform’s propensity to spread misinformation and foster extremism. Perhaps most of all, we need them to speak up about the internal culture that allows Facebook’s leaders to pretend to be listening to critics while privately conspiring to trample them.

A crack in the façade appeared, at last, this week. In his final days as a Facebook employee, on Nov. 8, Mark Luckie had circulated a memo accusing the company of “failing its black employees and its black users.” In it, he argued persuasively that Facebook’s efforts to promote diversity and inclusion have been largely cosmetic, and that the company’s machinery still conspires to squelch the voices, interests, and concerns of people of color. This week, Luckie took an even bolder step: He posted his memo publicly on Facebook. Luckie told CNN that he made the memo public because “Facebook does not make any meaningful change on a company level unless it is being held accountable publicly.”

It’s clear by now that Facebook’s leaders respond to outside criticism defensively—and sometimes even offensively.

Predictably, company officials responded by portraying Luckie’s experiences as unrepresentative and questioning his motives for going public—easier to do now that he’s gone. But Luckie was right: They’re now being forced to reckon with his arguments in a way that they didn’t when he raised them privately. And some others who still work at Facebook were emboldened to respond supportively to his post. One black employee thanked him for “articulating what I’ve so often thought and felt and not been able to say.”

Perhaps Facebook will try to squash her, and others who speak up, like the proverbial bug. But that will be a lot harder now that the dissent is being voiced in public. That’s the thing about speaking out: It’s contagious. There’s strength in numbers, a strength that Google’s employees harnessed by organizing mass walkouts and signing their names to open letters. It may be true that speaking out isn’t part of Facebook’s corporate culture—today. But cultures can change. Until recently, it wasn’t part of Google’s culture, either. Now it is, and both Google and the world are better off for it.

Facebook’s leaders and many of its employees may feel that Luckie betrayed the family. But when the family is hurting people, the real betrayal is to remain silent.