In the tense days after an unarmed Black teen was killed by a White police officer in Ferguson, Mo., Justin Edmund wondered why no one else in Silicon Valley was talking about it. "Why would they bother?" he wrote in an essay on Medium. "At most major technology companies, an average 2% of their workforce is African Americans — we're talking tens of people at companies employing thousands of people. At my own company, it's even worse at only 1%. I can count us all on one hand."

The seventh employee at Pinterest, Edmund, 24, is a designer responsible for the look and feel of key features on the site, which acts as a digital clipboard for users to share photos of hobbies and interests, say wedding cakes or vintage hats.

Yet, as a young African-American man, he feels isolated, one of the few people who looks like him in the company where he works and in the Mission District neighborhood of San Francisco where he lives.