[ugh]

It would be illegal, yes. You are allowed to keep the photo but not to publish it.

Kunsturheberrechtsgesetzes (KunstUhrG) §22, first sentence: „Bildnisse dürfen nur mit Einwilligung des Abgebildeten verbreitet oder öffentlich zur Schau gestellt werden.“ (Rough translation: “Images can only be published with consent of the depicted.”)

Here’s the whole text (German): http://dejure.org/gesetze/KunstUrhG/22.html

§23 lists all the exceptions:

1. Photos with some sort of historic meaning.

2. Whenever the depicted persons are merely incidental to the actual subject.

3. Photos of gatherings, demonstrations and similar such events.

4. Basically, if it’s art.

[bcrawford]

The guy in the video is dancing. Dancing is art.

Settled.