Facebook CEO Mark Zuckerberg had to scold his staff after discovering that unidentified employees recently crossed out "black lives matter" and replaced it with "all lives matter" on the walls at Facebook headquarters — multiple times. Gizmodo obtained an internal memo written by Zuckerberg and posted on a company-wide announcement page, in which he described the acts as "unacceptable" and "malicious," and noted that he already warned employees about it last week during a Q&A session.

"Despite my clear communication at Q&A last week that this was unacceptable, and messages from several other leaders from across this company, this has happened again," Zuckerberg wrote. "I was already very disappointed by this disrespectful behavior before, but after my communication I now consider this malicious as well. There are specific issues affecting the black community in the United States, coming from a history of oppression and racism. ‘Black lives matter’ doesn’t mean other lives don’t — it’s simply asking that the black community also achieves the justice they deserve."

"This has been a deeply hurtful and tiresome experience for the black community and really for the entire Facebook community"

Facebook allows its employees to write on walls at its Menlo Park headquarters, but according to Zuckerberg, has yet to implement rules about what can be written. The social network — just like the rest of Silicon Valley and the larger tech industry as a whole — is very white and largely male. Facebook is 55 percent white and 68 percent male by its own count, with black people making up only 2 percent of the company (and that number somehow shrinks when you focus on tech workers).

Zuckerberg states in the memo that the company has launched an investigation to find out who was crossing out Black Lives Matter signage. "This has been a deeply hurtful and tiresome experience for the black community and really for the entire Facebook community, and we are now investigating the current incidents." While it's clear that Facebook has a major problem on its hands that it needs to immediately address, how far the company will go to remedy the issue is still up in the air.

"We are now investigating the current incidents."

Zuckerberg invited employees to a town hall about Black Lives Matter next week, but rarely has a 30-minute meeting changed anyone's outlook on society. Facebook (and the rest of the tech industry) needs to fix its diversity issues which are frankly ridiculous in 2016, and make sure every single employee understands that no one's voice should be quieted.

Facebook has not responded to a request for comment.