Reddit co-founder Alexis Ohanian has resigned from the tech firm's board and urged the company to replace him with a black candidate.
The 37-year-old tech entrepreneur, who is white, is the husband of tennis legend Serena Williams.
Ohanian decided to quit after days of violent protests across the US over the killing of African-American George Floyd, a 46-year-old man who died in Minneapolis on May 25 after a white police officer knelt on his neck for nearly nine minutes while the handcuffed man gasped for breath.
In a series of tweets on Friday, Ohanian said he was resigning, "as a father who needs to be able to answer his black daughter when she asks: 'What did you do?'"
"I've resigned as a member of the reddit board, I have urged them to fill my seat with a black candidate, + I will use future gains on my Reddit stock to serve the black community, chiefly to curb racial hate, and I'm starting with a pledge of $1M to @kaepernick7’s @yourrightscamp," he said.
"I co-founded @reddit 15 years ago to help people find community and a sense of belonging. It is long overdue to do the right thing. I'm doing this for me, for my family, and for my country," he said.
Ohanian and Williams married three years ago and they have one child.
"I believe resignation can actually be an act of leadership from people in power right now. To everyone fighting to fix our broken nation: do not stop," he said.
Based in San Francisco, Reddit is a social news aggregation, web content rating, and discussion website. It has millions of users and calls itself "the front page of the internet".
Ohanian founded the social media website 15 years ago with his college roommates Aaron Swartz and Steve Huffman. He stepped down from daily duties in 2018 but has retained a seat on the company's board until now.
Reddit CEO Huffman wrote in a post on Friday that the company would "honour" Ohanian's request to replace him with a black candidate.
"We're working with mods to change our content policy to explicitly address hate. u/kn0thing (Ohanian) has resigned from our board to fill his seat with a Black candidate, a request we will honor. I want to take responsibility for the history of our policies over the years that got us here, and we still have work to do," Huffman said.