I am not sure what country you are in, but if it brings you comfort, I spent about five hours searching court records in the US for evidence of them or their clients ever filing copyright lawsuits and found none. I am not saying don’t offer to pay something, just that you probably should not do anything out of fear of getting sued in the US.
If they were in the US, I would report them to the state bar for the unauthorized practice of law. However, I think they are only really in Germany.
If they were in the US, I would report them to the state bar for the unauthorized practice of law. However, I think they are only really in Germany.