The second last one reminds me of something:
Here in the UK, all mains plugs must have an earth(ground) pin, which is slightly longer than the live and neutral pins.
There are mechanical plastic shutters inside the socket that cover the live and neutral contacts, until the earth pin is inserted.
This means that the only way to electrocute yourself is to find something earth-pin-shaped, push that into the earth hole/slot, then find something conductive and push that into the live hole.
There are even rules saying that it should be impossible to insert the plug upside-down (that is, earth pin in, but live and neutral going over the top of the socket.
Despite all this, you can still get these:
http://www.fatallyflawed.org.uk/
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Also, which doofus decided that brown and blue were good colours for mains wiring?
We used to have:
red = live
green = earth
black = neutral
...which is far more intuitive.
I can't even remember which way round blue and brown are supposed to be right now.