FTA (Google Translate, slighty modified):
However, there were still "other channels" as Attorney Siegmund said: In the "Line D1" the spies took simply Youtube-videos on the Internet. Under harmless videos they put under collusive usernames hidden messages. And then there was, according to the investigators nor the agent Vintage bounce points, mainly in North Rhine-Westphalia. There, hidden mechanical engineer Andreas stop documents that were picked up by members of the Russian headquarters.
They were even links to accounts.. can't find a better source at the moment.
FTA (Google Translate, slighty modified): However, there were still "other channels" as Attorney Siegmund said: In the "Line D1" the spies took simply Youtube-videos on the Internet. Under harmless videos they put under collusive usernames hidden messages. And then there was, according to the investigators nor the agent Vintage bounce points, mainly in North Rhine-Westphalia. There, hidden mechanical engineer Andreas stop documents that were picked up by members of the Russian headquarters.
They were even links to accounts.. can't find a better source at the moment.