It's sentient and decides to hunt and kill you.

I wish for a goat uprising.

Granted. They were all eaten.

 

I wish for a supercomputer.

Granted, at the moment you turn it on, i yank out the RAM and HDD (hard disk drive), so it fails to boot,

then I cut the wires leading to the PSU, removing power to the computer's internals.

Next user falls 10km imto a 1m shallow pool

This isn't Survive The Attack...

But I open my parachute and land in the water at slow speeds.

 

I wish that cccp3 had posted in the right thread.

he does and you get banned

 

i wish that i could bend the will of my enemies

You bend the will of your enemies so that they may kill you.

I wish I owned Facebook.

You own it, but a user obsessed with the internet assassinates you for introducing Timeline.

 

I wish for many delicious, non-poisonous/deadly/radioactive cakes. That I can eat.