Am I responsible for fixing broken links under a Creative Commons Attribution-ShareAlike license?

Question

The Creative Commons Attribution-ShareAlike 4.0 International Public License states

1. If You Share the Licensed Material (including in modified form), You must:

   A. retain the following if it is supplied by the Licensor with the Licensed Material:

   . . .

   v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable

If, for my use of the license, I provide a direct link to the original material and the link rots or the page otherwise becomes inaccessible (for reasons which are not my fault), am I responsible for replacing it?

Answer 1

_{(based on reading the license as a layperson and non-native English speaker)}

No, you don’t have to fix a broken URI.
If the URI no longer points to the licensed material, you don’t have to supply it (nor any other URI that still/now does point to the material).

Section 3(a)(1)(A) uses this wording:

• ① retain
• ② if it is supplied by the Licensor
• ③ with the Licensed Material

① The word "retain" makes clear that you have to provide the URI as specified by the Licensors. So if they only specify http://example.org/my-work, you have to use exactly this URI, not any other URI (strictly speaking, not even https://example.org/my-work).

② The word "supplied" again makes clear that it’s only about the URI which they specified themselves.

③ The words "with the" narrow it down to the URI that is specified in (or next to) the work. So you don’t have to look elsewhere to find a suitable URI.

Furthermore, nowhere does 3(a) require that you would have to keep your attribution updated. You have to make your attribution once, when you share the material. What the Licensors do after that (e.g., change their names, change their website’s domain, or even remove the license) is of no concern to you.
The only exception is 3(a)(3), but this requires you (if the Licensors request it) to remove parts of the attribution (e.g., to remove the broken URI), not to replace them (e.g., to add the new URI).

Answer 2

If the link rots, and the original work cannot be found, you are not liable to fix it. If the original work however, had moved projects (from the closing Google Code to GitHub, for example), and this transition is public and well known, it's likely that you must change the link to reflect that, yes.

Answer 3

You are responsible for replacing it, as the license states, “to the extent reasonably practicable”.

Since the law and the contract do not provide any other indication, the only way to formally understand what “reasonably practicable” means is to study existing jurisprudence. In other words, it's up to judges to decide. I'm not aware of any existing jurisprudence on this particular topic.

For example, if you distribute printed flyers with the old URL, you are clearly not expected to fix the flyers that you handed out before the URL changed. But if you print a new batch where you've modified other parts of the text, and you were aware of the URL change, it's plausible that you could be required to update the URL.