The law does not need formal definitions like that. Law isn't programming, this is what nerds usually forget.

Legal definitions are usually based on common sense and the "flies like a duck, quacks like a duck, ..." principle.

A clumsy first approximation: If the purpose and intended use of the thing is to provide access to or greatly help in finding access to the infringing content, then it's "linking" to that content.

> The law does not need formal definitions like that. Law isn't programming, this is what nerds usually forget.

It is not about laws, but about experts opinions in judgments. Courts routinely hire lawyers and experts to redact very formal, technical, philosophical and nitpicky memos about a topic. The CJEU has a resident pool of such experts and they are all very qualified (and variegate in their political orientation).

Obviously those memos are not turned into law. We are talking about judgments here. But those memos are read and used by judges to inform their decisions. I would just love to get access to the memos that are surely being produced for this case.

Just because it doesn't have formal definitions doesn't mean it doesn't need them. As GP points out, the implication of the vagueness is that there will be a lot of legal uncertainty.

We absolutely don't want formal definitions for law. While it may seem like a good idea on first sight it would create more problems than it would solve. Lawmakers often forget some specific situations (or there is technical progress that wasn't taken into account) when writing the text of the law (or in this case the formal definition) but it's clear how their intent would be. Judges can decide those specific cases when they are on the table. Nobody can foresee everything.

There are many examples where case law differs from the exact wording of a law for a very good reason.

So, for example, having a service which provides a JSON file that contains a list of sites you know to be copyright-infringers, that would clearly be bad.

What if your purpose in publishing that JSON feed was to supply URLs to a content-blocker? Would that change of purpose matter?

Courts have been dealing with clever nitpickers like yourself for centuries. All of these would be hyperlinks according to the courts, and if you tried to argue otherwise you'd be told that you were trying to make a "distinction without a difference".

He is just curious at the specific definition the court is going to come up with. Were do they draw the line and how would they capture that in words?

It cuts both ways though. A judge could easily expand the definition of what a hyperlink was beyond what is reasonable due to vagueness in the law because the "reasonable person" test takes account for the people that think changing their desktop wallpaper is "magic" performed by "computer geniuses."

People have earned a lot of money by nitpicking laws.