[wolfgke]

> While it is a grey area, its not that untested. The tax office is a good proxy to define commercial vs non-commercial, and there should be plenty of precedence for different cases. In cases where the tax office don't consider something as commercial/for-profit/done under compensation and do not tax them as such, the copyright owner has a much weaker case to argue commercial activity.

At least for German websites you have to add an imprint (Impressumspflicht - there is no proper English translation of this that I know of since this is a concept that to my knowledge only exists in Germany). What content this has to contain depends on whether the website is to considered as commercial or not. What remains to be said is obvious: There are court decisions that say that there are completely different criteria for a website to be commercial (in the sense of the content of the imprint) than the criteria tax authorities apply.