Around April 10, Facebook CEO Mark Zuckerberg will testify before the Senate Judiciary Committee about internet privacy and the need for regulation in the wake of the Cambridge Analytica scandal. One way or another, what he says will be a powerful lesson for entrepreneurs, either in how to lead or how not to.

Zuck has reason to be nervous. After news broke that Cambridge Analytica harvested the private data of 50 million Facebook users (a major terms-of-service violation) to influence the 2016 election, the internet went ape-you-know-what. #DeleteFacebook trended. Op-eds screamed that deleting your Facebook account was an act of resistance. And as I write this, the company has lost about $80 billion in value.

Facebook hasn't exactly responded to this mess with speed, transparency, or humility. It took Zuckerberg five days to make any statement. When he did, he failed to do the one thing he had to do--apologize--until the next day. He said zip about the fact that Facebook knew about its security hole for two years and did nothing.

With Facebook hemorrhaging its members' trust, Zuckerberg has no choice but to go before Congress. But what will he say? What should he say? Twitter's been crushing him for insincerity, aloofness, and arrogance, while pundits say he doesn't appear to care that his users feel betrayed. This is how leaders go down, and sometimes, take their companies with them, too.

If Zuckerberg wants to save his job and his company, there are five things he must say to the Senate. I don't know if he'll say them, but even if he doesn't, we can learn from them.

1. "I'm sorry."

This is basic. Own the problem. Show remorse. Apologize. One of Zuckerberg's biggest blunders so far has been the "mistakes were made" gambit. That passive voice, weak tea, pseudo-apology is a way of dodging responsibility, and it won't fly here. Leaders of any organization, whether it has five employees or 50,000, know everything that happens on their watch is their responsibility.

If you screw up, you might not be able to dodge all the anger or avoid all the blowback, but saying "This is on me. I accept responsibility and I deeply regret what's happened" improves your chances. That's the one thing Zuckerberg has to do.

2. "This is what happened."

Zuckerberg needs to explain clearly and succinctly--in a way that the notoriously tech-phobic members of the Judiciary Committee can understand--how Cambridge Analytica was able to do what it did. The world doesn't want techno-babble; it wants answers. What happened? What weaknesses or bad decisions allowed it to happen? What other parties were responsible? In a crisis, information eases customers fears. It's the responsibility of the leader to provide that information, but also to curate it so people aren't overwhelmed.

3. "This is what we've done." 

This one is crucial. If Zuckerberg talks about "what we're planning to do," it's game over. He has to make it clear that Facebook has already taken decisive action to plug the data leaks and make sure this kind of thing never happens again. As a leader, you know your customers' trust is all you have. When that trust starts taking on water, you can't talk about what you will do, because nobody will believe that you'll keep your word. You choose a course of action, take positive steps, and keep your stakeholders informed every step of the way.

4. "This has been a serious blow."

Nobody wants to hear Zuckerberg spout platitudes about "learning valuable lessons" and how Facebook will come away from this stronger. No. PR spin will make him look like an out-of-touch billionaire jerk. This affair has gut-punched the company's finances and reputation and he has to acknowledge that.

Good leaders level with their stakeholders when things are dire. When you do that, you display respect for your people's ability to deal with the truth. You show that you understand how serious the situation is. You give everyone the chance to take a deep breath, crack their knuckles, and get to the hard work of fixing things. We'll see if Zuckerberg can own up to the damage.

5. "Whatever it takes."

Finally, senators will talk seriously about regulating Facebook, Google, Twitter, and other titans. When they do, Zuckerberg's only response should be 100 percent commitment. Behind closed doors, he and his fellow CEOs can argue about solutions, but in public, he must be totally on board with reform. When you're the leader, and your company has lost trust, you not only have to take strong action but also have to be the one cheerleading it. No equivocation, no waffling.

Remember, consumers learn more about your company's character by how you deal with a crisis than they do when everything's going smoothly. We'll soon see what we learn about Mr. Zuckerberg.