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.

>>25 : P not if it's under the floor

by the way, I tried Darik's boot & nuke, it sure as hell takes a long time. Lesee, it's cleared 8% of a 12GB hard drive after 10 minutes. I guess this wouldn't be good if they were right outside your house, you'd have to know they were coming about 5 hours before, because I know most people have bigger hard drives than 12GB.