Within 10 minutes of stepping onto the streets of SOMA, a young bearded man who couldn’t have been older than 35 started trailing me, screaming “you black fuck! Turn around. I’m talking to you, dirty nigger.” I turned to face him, and said, “I’d prefer you say that to my face, like a man,” at which point he did say it to my face like a man. If there wasn’t a security guard at the corner, I don’t even know. And then I walk into a coffee shop, where a dozen comfortably dressed white people are politely, quietly sipping their coffee, talking about valuations and haircuts. Of course, the other black man in there was old, bearded, and very homeless. He zeroed in on me, bee-lined it over, and began to tug at my jacket insistently. I took off my headphones, and he was asking aggressively, insistently, noisily, for some money. I asked him to step outside, and gave him a few bucks. I asked him to be polite, and not bother people inside stores, because that’s how people get arrested. I walked back in to a disapproving half-shake from the barista, a room of studiously avoiding gazes, and hip-hop quietly playing over the sound system. And, of course, when I sit down with my espresso and pull out my Karma* to hop online, two people recognize me from tech, and we proceed to geek out over sharing mobile data, and how much better all this exciting collaboration software will make the world.

*Where we are an investor.