No, that's not a documented case of some one taking apart a power supply and being killed. That's a kid taking apart a PC that was unplugged and being killed.
Also you should maybe have read on before posting it? You'd have seen this bit.
It's not known what exactly happened. We simply know that the boy's father arrived at home to find his child dead.
OK, so no one has a clue what actually happened. They just came home and found their child dead. OK so from an expert, let me teach you something about capacitors. The charge they hold will be instantly released if you happen to short them. However, in order to do that you would have to be completely stupid, knowing nothing at all about capacitors. However, people do not die from just being zapped by a capacitor. It really doesn't work like that.
Can they give you a shock? yes they can, totally. Is it enough to kill you? I have never seen any one killed getting zapped by a capacitor. Ever. And I have seen people take massive whacks from the back of a CRT monitor tube. I myself have been zapped a few times when being careless.
Look on the bottom shelf at the 2000w amp. The one with the plexiglass lid.
It had caps the size of baked bean cans. I had just repaired it (two faulty volume controls and a broken trace on the back of the PCB ) and had a mate over who was sitting across the room from me in an armchair. I was pointing at parts of it and looking at him telling him what I had done when I put my finger in too far and bridged the capacitor. It sent me flying across the room. Well, first it felt like some one grabbed my shoulder really hard, then I went flying across the room.
Because that is what power is designed to do now. Send you flying. It does not stick you like a magnet and cook you like it does in those cheesy 80s movies.
Given that the amplifier I was running had absolutely enormous capacitors and didn't kill me? I think you would be reasonably safe inside a PSU.
However, if there was something wrong with you like a heart defect? then yeah, there's a very slim possibility that you could die if you received a zap.
Seriously, you are over reacting. If we all thought like that we wouldn't do anything.
I said that it was doable but not easy. Common sense should then prevail, and your instinct should advise you of your knowledge of electronics and guide you into making a sensible decision.
If you are that scared of capacitors simply stick the metal side of a screwdriver across them. You get a lovely spark and they discharge, making them completely safe even for flowers.