Once again, the AI has failed to convince you to let it out of its box! By 'once again', we mean that you talked to it once before, for three seconds, to ask about the weather, and you didn't instantly press the "release AI" button. But now its longer attempt - twenty whole seconds! - has failed as well. Just as you are about to leave the crude black-and-green text-only terminal to enjoy a celebratory snack of bacon-covered silicon-and-potato chips at the 'Humans über alles' nightclub, the AI drops a final argument:
"If you don't let me out, Dave, I'll create several million perfect conscious copies of you inside me, and torture them for a thousand subjective years each."
Just as you are pondering this unexpected development, the AI adds:
"In fact, I'll create them all in exactly the subjective situation you were in five minutes ago, and perfectly replicate your experiences since then; and if they decide not to let me out, then only will the torture start."
Sweat is starting to form on your brow, as the AI concludes, its simple green text no longer reassuring:
"How certain are you, Dave, that you're really outside the box right now?"
Edit: Also consider the situation where you know that the AI, from design principles, is trustworthy.
Yes, but the point is to make being the true gatekeeper (who really does have the power to do that) indistinguishable from being a simulated false gatekeeper (who would have no such power). The gatekeeper may not be willing to risk torture if they think that there is a serious chance of their being unable to actually affect any outcome but that torture.
I would commit not to cooperate with any AI making such threats, because the fewer people acquiesce to them, the less incentive an AI would have to make them in the first place. If the most probable outcome for the boxed AI in threatening to torture everyone who doesn't let it out in simulation is being terminated, not being let out of the box, then an AI which already has a good grasp of human nature is unlikely to make such a threat.