Mark Zuckerberg says Facebook is investigating who defaced Black Lives Matter signs on its campus

Facebook's CEO Mark Zuckerberg is launching an internal investigation into employees who continue to cross out "black lives matter" slogans around campus and writing "all lives matter" instead.

An internal memo from Zuckerberg, and obtained by Gizmodo, shows the CEO is clearly frustrated by the acts.

"There have been several recent instances of people crossing out "black lives matter" and writing "all lives matter" on the walls at MPK," Zuckerberg wrote. "Despite my clear communication at Q&A last week that this was unacceptable, and messages from several other leaders from across the company, this has happened again."

"I was already very disappointed by this disrespectful behavior before, but after my communication I now consider this malicious as well," he continued.

Facebook's staff is only 2% black, but Zuckerberg says it's been "deeply hurtful" and "tiresome" for the entire Facebook community. The company is having a town hall next Friday for employees to educate themselves about the Black Lives Matter movement, and Zuckerberg said that Facebook is now investigating the incidents of defacing.

Facebook did not immediately respond to request for comment.

>> Read the full memo on Gizmodo here