Who here is attempting to disprove aliens?
As Harry already pointed out, the burden of proof lies on the claimant. The more extraordinary the claim, the more extraordinary the evidence must be.
What I want to know is what makes anyone think the thread is about proving or disproving aliens or debating their existence. The intent of the thread was to take a poll. Presumably to see how many people believe vs how many that don't.
Nothing in that suggests either side has to prove or disprove their stance and no where is it required to try to change peoples minds (debate).