>>9what if cops are already knocking at your door, and you hdd is full of unencrypted child porn?
You can mechanically damage HDD, but forensics experts have special hardware, where they can mount magnetic discs from any hdd and read them. So damaging HDD would only prolong your sentence by obstructing justice charges. Guess using SSD is the only viable alternative. You can quickly kill SSD by passing high voltage into it.