A small update to this story.
Today the Supreme Council ruled that the court case against the Hofstad group must be retried (NL). This cane after the public prosecutor appealed a decision by Court of Appeals in The Hague. Earlier in 2008 the The Hague court of appeal acquitted all members of the Hofstad group of 'membership of a terrorist organisation' .
The Supreme Council ruled that the The Hague court of appeal had applied the legal definition of 'membership of a terrorist organisation' too strictly and hence invalid. The case must now be tried before a different court of appeal, probably in Amsterdam.