Authorities in Hamburg, Germany, said that they had shut down the mosque where several of the hijackers involved in the September 11 attacks had met because it remained a source of radicalization nearly a decade later: “Behind the scenes, a supposed cultural organization shamelessly used the freedoms of our democratic rule of law to promote holy war,” said Christoph Ahlhaus, secretary of the interior for the city of Hamburg, at a news conference: In addition to closing the mosque, the authorities banned the cultural association that ran it, which was founded in 1993.
via:[http://www.nytimes.com/2010/08/10/world/europe/10germany-.html]