memfd_secret() in 5.14

> As mentioned, potentially waking up and causing a fire.

Any device with a Lithium-Ion battery can catch fire, whether it's drawing power or not. And even if your device is shut down (not even hibernating), you could also trigger your power button accidentally. (Hasn't happened to me with a laptop yet, but has happened countless times with my cell phone, causing it to reboot.)

Was there a risk 30 years ago when there was no thermal throttling and no thermal cutoffs in devices, especially CPUs? Sure. Is there a non-zero risk that any device that contains energy storage catches fire? Absolutely. But hardware has come a long way since then to mitigate those risks and I think this concern is overblown. Heck, even 15 years ago with my then laptop I had a couple of times when it didn't even enter sleep (stochastic bugs in hardware and/or the kernel) and I didn't check before putting it into the bag because I was in a hurry. And while the inside of the bag got warm to the touch (at most 40C), nothing got really hot, the laptop throttled down and just drained its battery much quicker than in suspend mode, causing it to shut off and causing me some inconvenience.

Millions of people put their laptop in sleep mode in their bags daily, and I've yet to see an epidemic of cases where laptops catch fire due to this. The data just doesn't bear out that this is an issue that one should be concerned about. Your device catching fire because the manufacturer did a bad job with that specific model is by far a much likelier outcome than it catching fire due to being stuffed into a bag in suspend mode.

I'm not against hibernate, and I think that hibernating laptops is a very legitimate use case, especially if you want to leave it off (without draining battery) for a significant amount of time. But please don't argue for your position with fear-mongering against other legitimate ways of using your own device.