No they don't - but in this case we're just talking about the number of permutations. What people choose to select is up to them.
But I was just being pedantic really (and you're right about that lottery thing.)
Unless it's done by PM, but I suspect the point of this is to increase site visits and activity. So that's that knackered.
Or if there was a way of ENCRYPTING our responses like in SPOOKS.