They received a letter threatening a lawsuit due to the fact that they had a newsletter sign up form without double opt-in feature on their site and some explicit legal documentation missing. Other than that it was a really simple presentational site made in Wordpress. Our business relationship ended years ago but I received a mail from them years ago asking for help in putting those things in because they were afraid of having to deal with legal stuff over such small bs. I obviously did.

Now I don't know German law, as I'm not German, but it felt like they were really afraid that it could happen.