LOL its true man.. its damn crazy when those things blow out..
It happened only once to me.. Though I wasnt the one working on that car..
Still scared the shit out of me..
:o
Lets put it this way.. If you take your car to an audio shop, they'll disconnect the neg before doing any electrical work, or going under dash...
At home, when I'm just taking my HU out, I wont really disconnect it.. But, its definately a wise thing to do.