Several countries have interfered with or banned access to the social networking website Facebook, including China, Iran, and North Korea. Use of the website has also been restricted in other ways in other countries. As of May 2016, the only countries to ban access around the clock to the social networking site are China, Iran, and North Korea. However, since the vast majority of North Korean residents do not have access to the internet, China and Iran are the only countries where access to Facebook is actively restricted in a wholesale manner.
NKwas invoked but never defined (see the help page).