On September 12th, betwenn 20 and 30.000 people protested against the surveillance state in Berlin. The demonstration was a huge success and made it into mainstream television news. The event was overshadowed by the police itself, that seemed unhappy with the critique. This is how at least two of them reacted that day:

freiheit statt angst / freedom not fear - demo 12.09.2009 from Gerd Eist on Vimeo.

The protesters were peaceful and nothing special could have caused such action. The police only stoped the action after a crowd started to shout: "We are peaceful, what are you?".