Let us suppose I am talking to a thief who steals cars daily. I ask him
Yo!, at what time do you steal cars?
To which he replies
Cars are stolen at 1 am.
Now I think that the sentence is valid grammatically but I am not sure if he used it 'right'. By 'right' I mean right with respect to the question. Also I suspect it has something to do with 'Active/Passive Voice'.