My university recently put a staff member on leave of absence after the staffer took a weekend kayaking trip with several students, citing "unprofessional conduct". The staffer is a kayaking instructor for the university, and the students were all experienced kayakers and not (to my knowledge) his students.
This seems to me to be effectively a prohibition on staffers being friends with students. Is there a precedent for this? What business is it of the university to police what staff and students do in their own free time?