[sdiy] Grounding & computers

[Synthusiast]

Hi list,

Talking about all this grounding stuff, I wondered if you could answer this
grounding question I've been wondering about for a long time.

My computer isn't grounded. I don't even have a ground socket here in the
room. The mains voltage here in Europe is about 220 V. Now why is it that
the voltage level of my computer casing has to be at 110V from earth level?
If I touch the computer casing with one hand and the grounded cable tv plug
with my other, I can do some nice instant Michael Jackson dancing stuff
without any practicing... Now why did they do this?

Cheers,
Martijn