Women in Brussels 'filmed without their knowledge' by men wearing Meta smart glasses
(www.brusselstimes.com)
Filming by itself isn't illegal in Germany, but publishing the footage without consent of everyone in the video is. ("Recht am eigenen Bild") Don't know how this applies if the perpetrator is from the USA and publishes the recording there, though.
And even if - good luck in suing someone from the US while you're still in Germany.