Bed yanks you from a dead sleep into a sealed metal box

I’d think with this bed, an “earthquake” would become a secondary concern, to the potential heart attack, from being rapidly wrenched from a dead sleep and into a metal box… And that’s before you come to realize you’ll likely be in that box for a few days… surely not much longer.
Not to be obvious but having this bed, with a few minor changes, would mean that whoever you could get to “lay in the bed”, you could literally “capture” them, and have em sealed up tight, in a steel box. They wouldn’t even know what had happened. In a split second, they’re sucked into some black hole, and it’s lights out.
Then you could let ‘em out, and everyone would just laugh and laugh… that’d be one scenario.