I'm not sure I would call it that at all. Silicon Valley is not the world and, in the corporate world, this remains a very California / Silicon Valley phenomeno

I'm not sure I would call it that at all. Silicon Valley is not the world and, in the corporate world, this remains a very California / Silicon Valley phenomenon (present but less strong in a few key other places — New York, Seattle, Portland come to mind). It is of course also a university-campus phenomenon (especially private universities) but those aren't really "corpo". For that matter, the Wikimedia Foundation is only "corpo" insofar as a 501(c)(3) is technically in fact a corporation — unlikely to be within the meaning of what you intended. On that note, it is more prominent in the nonprofit sector, perhaps due to volunteers being more predisposed to activism in general. (Mozilla was a bellwether.)