I have heard that there are some supervisors abusing their students, pushing for progress and insulting them when the progress is not ideal, or even assign task

I have heard that there are some supervisors abusing their students, pushing for progress and insulting them when the progress is not ideal, or even assign tasks unrelated to their research (projects from their company?). Effectively their supervisors are controlling their leave. I guess the current situation really depends on supervisor, so it would be nice if there are laws for students' basic right.