Akademik

black hole
noun
a) A gravitationally domineering celestial body with an event horizon from which even light cannot escape; the most dense material in the universe, condensed into a singularity, usually formed by a collapsing massive star.

Julien Pain, head of the Internet desk at Reporters Without Borders, a Paris-based group which tracks censorship around the world, put it more bluntly. “It is by far the worst Internet black hole,” he said.

b) A sphere of influence into which or from which communication or similar activity is precluded.

youll have to love U.S. District Court Judge John Kanes decision to keep Denver-based Exactis.com out of an Internet black hole.... MAPS maintains a database of Internet addresses that it believes send or relay spam. It’s called the "Realtime Blackhole List<!,"

Ant: white hole

Wikipedia foundation.