Teachers are facing death threats, abuse and allegations of serious crimes by pupils and parents through social networking sites, a poll suggests. One was even told her throat would be slit, while another was accused of being a rapist. Online abuse of teachers is widespread, with more than two-fifths (42%) of those questioned saying they had been a victim of it, a survey by the NASUWT teaching union has found. Of those, more than three-fifths (61.2%) said a pupil had written an insulting comment...