Quoting Cervisia :

> robots.txt. This is not the law

In Germany, it is the law. § 44b UrhG says (translated):

(1) Text and data mining is the automated analysis of one or more digital or digitized works to obtain information, in particular about patterns, trends, and correlations.

(2) Reproductions of lawfully accessible works for text and data mining are permitted. These reproductions must be deleted when they are no longer needed for text and data mining.

(3) Uses pursuant to paragraph 2, sentence 1, are only permitted if the rights holder has not reserved these rights. A reservation of rights for works accessible online is only effective if it is in machine-readable form.

-- https://news.ycombinator.com/item?id=45776825