German copyright law has no Fair Use. There are copyright exemptions for private or academic use, but commercial use has no such exemption. Books have special protection even according to § 53 (4) b).
And yes, it's the duplication which is illegal, not the publication of them.
And yes, it's the duplication which is illegal, not the publication of them.
[1]: https://www.gesetze-im-internet.de/urhg/__53.html