I never heard of this phenomenon–cell phones in the bet medrash. Turning them off seems only common sense. Israel is a cell-phone heavy society, and our shuls are very informal–but I have never heard a cell phone go off where I daven or learn.
University laboratories, lecture halls, and libraries have no-cell-phone rules. Cell phones in a Shul or Bet Medrash? And they need a Rav to tell them that this is unacceptable? I agree with Joseph–this is not drastic- call it a reminder of derech eretz.