How to explode a hard drive

I know this isn't strictly tech, but I felt it's the best place for it.

People talk (on 4chan and such places) of raids by the police on their house to recover hard drives due to suspicions of CP or of pirated content.
I was wondering if anyone knew of a case where someone actually managed to destroy their Hard Drive, either remotley or before anyone could get to it, or any stories of the sort.
Could it hypothetically be fitted with some sort of... remote water filling thing?
Post anything relevant please.

explode a HD? smash it with a sledge hammer? theres also a floppy disk u can make that nukes a hd, but that takes time. and theres also the issue of the cops jsut raiding your house, theyd have to ask you to search it first, even before getitng the warrant. piracy isnt THAT illegal, mind you. and by then youd have plenty time to use a D's boot&nuke. (isnt called D's boot&nuke?)