Approximately 1500 pillow fighters descended on the Hauptwache, in the city center of Frankfurt. All subtly carrying pillows. At the strike of 4:00 PM, all hell broke loose as pillows started flying.
Great fun, and an interesting experience. By 4:30 the entire area was covered in feathers.
Apparently this was held in a variety of cities. Locally organized on Facebook. The police seemed a bit surprised, but took it all in stride.