The passive voice is famous for its vagueness. It lets us say what happened, without mentioning who did it. In fact, this is often the only thing that people know about the passive, and it leads to anything vague being labelled as passive.
But ‘passive’ refers to a very particular grammatical construction, and I think we should get our terms straight. So in the interests of public education, here is a list of ways that we can be vague about agency without using the passive. The next time someone says something is ‘passive’, check here to see if it really is.