Why students checking facebook on class are regarded disrespectful, while a professor who checks his facebook on a symposium as another professor is reading his paper is said to be cute and cool？ Are there absolute boundaries between righteous and evil, right and wrong?
I wouldn't regard such a Facebook-checking colleague as "cute and cool". Besides the fact that wanting to check a Facebook page already disqualifies one from being cool, it is disrespectful. I don't allow my students to use computers, cell phones, etc. during class, and if I were organizing a conference I'd strongly discourage those in the audience from doing so as well.