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.

There are many, many ways to safeguard your computer against confiscation, from programs that perform military deletes if a bad password or other signal is used, to various amounts of explosives in the case, and ten kinds of other things.  One guy doing illegal things with his machine rigged the doorframe of his bedroom with high-power magnets, effectively destroying his computer's hard drive when it was confiscated.

However, the police know about most of these protection schemes already.  When a seach warrant is issued in connection with computer crime, special teams that include bomb squad members and "white hat" crackers are assembled to search for and deactivate this crap.