Banning Islamist organizations doesn’t seem to be all that difficult. Although the next one will just pop up a few hours later.

But banning other forms of Muslim interaction in Germany has proven to be practically impossible.
Germany news: Interior Ministry bans ‘Muslim Interactive’ – The Interior Ministry has also searched the premises of other Islamist organizations in Hamburg, Berlin and Hesse. Meanwhile, the foreign minister has caused an uproar with comments on Syria.