This week, Facebook CEO Mark Zuckerberg scolded “malicious” employees for crossing out and replacing the phrase “Black Lives Matter” with “All Lives Matter” on a wall at the company’s Menlo Park headquarters.

The wall is meant to allow staff to express random thoughts on it. Zuckerberg sent the message in a private, internal memo addressed to Facebook employees.

According to Silicon Beat, the memo was first attained by Gizmodo, which took a screenshot of the message. In it, Zuckerberg said that he and other Facebook heads had warned employees to cease the behavior, but to no avail. He said the “disrespectful behavior” had now become “malicious as well,” and that the company is investigating the incidents.

He went further, essentially endorsing the “Black Lives Matter” movement.

“There are specific issues affecting the black community in the United Sates, coming from a history of oppression and racism,” Zuckerberg wrote. “‘Black lives matter’ doesn’t mean other lives don’t — it’s simply asking that the black community also achieves the justice they deserve.”

Megan Rose Dickey of Tech Crunch posted an op-ed article about the incident where she said “Zuckerberg is asking his employees to stop being ignorant and racist (my words, not his).” The same article points out that about two percent of Facebook’s workforce is black, while three percent is Hispanic: “[N]o surprises here.” Dickey adds, “55 percent of Facebook is white.” (The rest, presumably, are Asian or “other.”)

The Black Lives Matter movement took off following the shooting death of unarmed teenager Michael Brown, 18, in Ferguson, Missouri in 2014. A grand jury declined to indict Officer Darren Wilson it was discovered that Brown had attempted to grab the officer’s gun. Subsequent investigation by the Obama administration Department of Justice further debunked the “hands up, don’t shoot” narrative.

“This has been a deeply hurtful and tiresome experience for the black community and really the entire Facebook community,” Zuckerberg wrote in his memo. He signed off by encouraging all of his employees to participate in a special town hall scheduled for March 4 “to educate themselves about what the Black Lives Matter movement is about.”

Follow Adelle Nazarian on Twitter @AdelleNaz.