Across tech and the world of business, efforts to improve diversity are all the rage. But most company CEOs hand off responsibility for hiring more women and minorities to other executives, rarely getting directly involved with the initiatives themselves.

AT&T's Randall Stephenson is not like most CEOs.

On September 23, Stephenson delivered a powerful speech on race relations in America that is now going viral. Speaking at a conference of thousands of diverse AT&T employees, Stephenson took a powerful stance on issues surrounding Black Lives Matter.

"When a parent says 'I love my son,' you don't say 'What about your daughter?' ... And when a person struggling with what's been broadcast on our airways says 'Black lives matter,' we should not say 'All lives matter,'" Stephenson said, before getting cut off by thunderous applause from his employees.

Stephenson is the epitome of how a CEO of a company trying to become more diverse should act. His direct involvement in helping employees sympathize and understand one another sets a tone that the rest of AT&T's more than 200,000 employees can follow.

"If this is a dialogue that's going to begin at AT&T, I feel like it probably ought to start with me," he said.

In tech, companies like Google, Facebook, Apple, Twitter and others release annual diversity reports, announce countless diversity initiatives, and toss millions of dollars at the problem. Still, none of the CEOs of such companies serve as the face of those efforts. Just last month, the organizers of Tech Inclusion, a group that helps companies with their diversity efforts, had to post on social media to ask if there was any tech CEO who would want to speak at their conference.

That's why Stephenson's speech sets such an important example for other CEOs to follow. If you care about diversity, make it public so your employees and your peers know.

"The CEO sets the tone for the company," says Y-Vonne Hutchinson, diversity consultant and co-founder of Project Include, an organization that works with tech companies to help them improve their diversity. "CEOs shape their company culture not only in the initial stages of a company's development, but on a day-to-day basis, with every interaction they have."

One other prominent CEO has proven a rare exception when it comes to taking public action: Slack's Stewart Butterfield. Though he has not spoken as publicly about diversity as Stephenson, Butterfield has made his feelings on the matter clear. He wrote a note explaining to employees why they were given Martin Luther King Jr. Day off. He has hired numerous leaders in the tech diversity movement. He has let his minority employees bask in glory when Slack won an award, and most recently, he approved a broad expansion into Toronto that will make it easier for Slack--Inc.'s 2015 company of the year--to hire more diverse candidates.

"A CEO that is an ally and that publicly and privately supports and advocates for diversity and inclusion inside and outside a company sets the tone on the importance of diversity and inclusion," says Leslie Miley, Slack's director of engineering and a leader in the tech diversity movement. "It encourages people within the organization to become more vocal and to become allies, and lessens the possibility that people will be marginalized for taking on this important work."