Absolutely unacceptable behaviour but I'm also not surprised. Funding in my PhD was terrible and my department alloted TA positions. RA positions were shrouded in ambiguity wrt when it was deserved. Faculties rather than profs should be responsible for student funding. 1/
Anna MeierA professor in Tufts University’s School of Engineering required one of his international graduate students to work an unpaid TA job this past spring semester. After she went to her union and blew the whistle, Tufts withdrew her from her program. A thread of rage. 1/