As is discussed in various places, German law requires an "imprint"/"Impressum" (a page with some contact information, such as a physical address and an e-mail address, on the person responsible for the site) for virtually every1 website.
In a recent question, it was asked whether this also applies to sites hosted on Github Pages. That question can be answered in a pretty straightforward way (sites hosted on Github Pages are basically no different from any other website, as the author has full and sole control over the appearance of the page.
This question refers to the default appearance of projects on Github, though. Authors have no influence on the general appearance of these projects, as Github displays them in their default layout. The introductory page of a project displays the repository content (the files stored for the project) and is arguably somewhat customizeable in that the content of a file called
readme.md from the repository will be displayed below the files list, if it exists.
Now, "common sense" (sorry, could not resist) would tell me that Github owns and controls this page and is thus the first point of contact for any "official" activity. However, it seems that German courts are increasingly ruling that placing, or at least linking to such an "imprint" is also required on various social network profile sites such as Facebook or Google+2. On the other hand, the requirement for an "imprint" on business social networks such as Xing and LinkedIn seems to be disputed even for businesses presenting themselves there3.
Therefore, my question is: Is at least the requirement of an "imprint" on social media profiles limited to actually commercial enterprises, or are all German owners of Github projects who do not link to an "imprint" in their
readme.md (if even that is sufficient, given that this link may not be intuitively discoverable) vulnerable to receiving costly cease-and-desist letters?
Related bonus "question": Exemplary links to Github projects by German owners that are "doing it right" are appreciated.
1: There are some exceptions for "purely personal" sites, but any information I can find in German implies that nothing that might be of interest to any stranger on the web can possibly "purely personal" in the interpretation of German courts.