Ugh. I don't normally work from a cafe, but today I have the pleasure of sitting next to 2 self-aggrandized, faux-entitled white tech bros with more money than common sense and very few social mores. Their conversation includes so much of what is wrong with rich white dudes.
"Stealth" I have no idea, though I wish I did know so that I could avoid it, but I suspect they are trying to disrupt and re-invent something like composting streetlights or smart door hinges...