I am d/fed and as such ordinary JWs preaching in my area should know not to call at my door; but on occassion they still do and I just politely tell them that they should not be calling at my door.
Isn't that what enables these people?
They impolitely call at a door they are not supposed to call at.
You politely tell them to leave.
So they will be back, again and again.
Of course, what Danny supposedly did just makes martyrs of them, so win win for them.