Swiss Internet providers are coming under increasing pressure to block access to websites containing right-wing material. It follows the discovery of thousands of sites worldwide spreading racist propaganda and inciting sympathisers to violence.
Although Swiss providers themselves do not permit racist sites, they take no responsibility for preventing surfers from entering extremist sites via foreign providers.
The current situation worries private groups such as the Basel-based Children of the Holocaust Action (AkdH), which is concerned at the huge amount of racist material on the web.
The group has successfully lobbied the main Swiss Internet providers - Sunrise/diAx, Tiscalinet and Swisscom/Bluewin's IP-Plus - to block access to hundreds of neo-Nazi sites through the American Internet provider Front14. But racist material continues to be available through other, mainly American, sources.
Samuel Althof of the AkdH says his organisation has a good relationship with the Swiss providers, which are generally sensitive to the problem. But he criticises Cablecom for its uncooperative approach.
A Cablecom spokesman rejected the criticism, saying freedom of speech and legal uncertainties meant the company had to proceed very carefully.
The Swiss Institute for Comparative Law at Lausanne is one of several bodies working to track down racist sites on the web.
The institute's Béatrice Métraux told a Council of Europe convention on Tuesday that it had so far traced 4,000 extremist sites, more than half of them based in the United States.
Métraux said that strict European legislation meant that European countries were better placed to fight racism and xenophobia than the US, where the first amendment to the constitution forbids any restriction on freedom of expression.
As a means of tackling the European problem she called for a ban on domestic Internet servers providing access to foreign racist material.
swissinfo with agencies