Mafia 83. Doctor Who: Aliens in London

Actually, it's the opposite. It's impossible to identify someone who doesn't write. Only through some kind of non-disclosure agreement. But you can determine the stance of someone who does write. Both positive and negative.
Therefore, if dealing with non-active players is essentially a gamble, you can somehow determine the stance of active players.
And simply, from a moral standpoint - we've gathered to play, not just to send non-disclosure agreements.