For floppy disks, the only tale I have is from when we discovered that inserting an empty 3.5" case into the school machines would instantly crash the school PCs. I forget the brand, mosly likely M3s or Compaqs that were running Windows 98.
We had some fun with that, helped by the fact that the PC just went down instantly without even a BSOD.
More recently, I lost an SD card inside my home machine - it has a multi card reader, and it turns out that the CF slot does not have an internal enclosure top or bottom. Card naturally slipped right inside the casing when I missed the correct slot.
Thankfully quickly fixed with a screwdriver to take it to peices