I've always been surprised this doesn't happen more often.
Or maybe it just isn't reported.

Cyber protest targets UN website

The United Nation's official website appears to have been hacked in a form of "cyber-protest" against Israeli and US policies in the Middle East.

A message appearing on the site early on Sunday said:

"Hacked By kerem125 M0sted and Gsy That is CyberProtest Hey Ysrail and Usa dont kill children and other people Peace for ever No war."

Several web pages of the subsite for comments and news about Ban Ki-moon, the UN secretary-general, were affected and that section of the UN website was taken offline temporarily.

At least I like their message!!