Students at Southern Illinois University at Carbondale were surprised to discover last week that their posts were being deleted from the university’s official Facebook page. The censoring of comments began shortly after a union representing faculty members announced Wednesday night that it was going on strike, following months of heated negotiations with the administration.

Students said their comments were being individually deleted every few minutes, and finally all posts were disabled. The decision was made in an attempt to stop posts that were “pretty nasty and pretty rude and not acceptable,” Rod Sievers, a university spokesman, told the student-run newspaper, The Daily Egyptian. But one student told the paper it appeared at first that only pro-union posts were being deleted, and some students said they are now wondering about their freedom of speech.