Unlike some filtering systems, it works on a page by page basis rather than an entire domain.

FORBES: Connect

The speed with which websites can spring up and move can also catch out some filtering systems, said Mr Haggart.

BBC: The problems of finding filth

But, said Mr Haggart, many filtering systems are too crude and let through sites they should block and stop those that are innocent.

BBC: The problems of finding filth

Many filtering programs take a very blunt approach to web-based systems with which currently they cannot adequately deal.

BBC: Net filters fail the children

Such systems exist in their infancy, like the ratings on Amazon.com and the filtering provided in Slashdot.org.

CNN: Commentary: Internet can strengthen democracy