A regulation banning conduct by state university students that threatens or endangers the health or safety of any person including intimidation and harassment (5 Cal. Code Regs. 41301(b)(7)) is not unconstitutionally overbroad or vague—the words threatens or endangers health or safety give context and meaning to the prohibited intimidation and harassment. The university also did not violate the First Amendment in applying that regulation to discipline a student who barged into professors’ personal offices, videotaping the encounters, and asking them hostile questions about a poem which he found offensive and which had been published in a school newspaper. The professors confronted in their own offices in this manner might well have felt intimidated or harassed and feared for their safety. Nevertheless, O’Brien alleged sufficient facts to state a claim that the disciplinary action had been brought against him in retaliation for protected First Amendment activities he had undertaken before the incidents of interrogating the professors.