At the Stanford Graduate School of Business in Northern California, the stories got weird almost immediately upon their return for the fall semester. Students say they were being followed around campus by people wearing green vests telling them where they could and could not be, go, stop, chat or conduct even a socially distanced gathering. On the other side of the country, students at the Harvard Business School gathered for the new semester after being gently advised by the school’s top administrators, via email, that they were part of “a delicate experiment.”