[magnat]

Hard disks are surprisingly hard to destroy on-demand. There was a DEF CON 23 talk [1] exploring ways to quickly wipe your servers in situ using physical methods.

[1] https://www.youtube.com/watch?v=-bpX8YvNg6Y

[FRex]

I instantly though it was this (hilarious) one instead: https://www.youtube.com/watch?v=1M73USsXHdc

[jacquesm]

They should have used a plasma torch. Legal, relatively easy to contain too (just put a water bed below it).

[allenz]

Entertaining talk, but the best method is to discard the key for your fully encrypted disk. It's 2017, all your disks use FDE, right?

[zaarn]

SSDs internally yes. Any modern SSD simply uses some random key unless you specify another one. Shredding is as simple as telling it to shredder the key, end of story.

Some harddrives do this too, I believe but it's not as widespread yet.